diff --git a/.envrc b/.envrc
deleted file mode 100644
index 234188d..0000000
--- a/.envrc
+++ /dev/null
@@ -1 +0,0 @@
-PATH_add bin
diff --git a/.gitignore b/.gitignore
index 0a48702..921a949 100644
--- a/.gitignore
+++ b/.gitignore
@@ -22,6 +22,7 @@ doc
 # dummmy app
 test/dummy/log/*.log
 test/dummy/log/*.log*
+test/dummy/tmp
 
 rspec-persistence.txt
 
diff --git a/.rubocop.yml b/.rubocop.yml
index 2564b28..a724b9a 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1,5 +1,7 @@
+require: rubocop-rails
+
 AllCops:
-  TargetRubyVersion: 2.1
+  TargetRubyVersion: 2.5
   Exclude:
     - "bin/**/*"
     - "test/dummy/bin/**/*"
@@ -199,16 +201,3 @@ Style/DateTime:
   Exclude:
     - "lib/diaspora_federation/discovery/xrd_document.rb"
     - "spec/lib/diaspora_federation/discovery/xrd_document_spec.rb"
-
-### backward compatibility
-
-# only with ruby >= 2.3
-Layout/IndentHeredoc:
-  Enabled: false
-Layout/ClosingHeredocIndentation:
-  Enabled: false
-
-# for rails 4 and ruby < 2.2.2
-Rails/HttpPositionalArguments:
-  Exclude:
-    - "spec/controllers/diaspora_federation/rails4_spec.rb"
diff --git a/.ruby-version b/.ruby-version
index 6b4950e..5154b3f 100644
--- a/.ruby-version
+++ b/.ruby-version
@@ -1 +1 @@
-2.4
+2.6
diff --git a/.travis.yml b/.travis.yml
index 6622592..69c695b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,21 +1,12 @@
 language: ruby
 
 rvm:
-  - 2.5.5
-  - 2.4.5
-  - 2.3.8
-  - 2.2.10
-  - 2.1
+  - 2.6.5
+  - 2.5.7
 gemfile:
   - Gemfile
-  - test/gemfiles/rails4.Gemfile
   - test/gemfiles/no-rails.Gemfile
 
-matrix:
-  exclude:
-    - rvm: 2.1
-      gemfile: Gemfile
-
 sudo: false
 cache:
   bundler: true
diff --git a/Gemfile b/Gemfile
index 0897dae..c67d4fc 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 source "https://rubygems.org"
 
 # Declare your gem's dependencies in diaspora_federation.gemspec.
@@ -17,9 +19,10 @@ end
 
 group :development do
   # code style
-  gem "pronto",         "0.9.5",  require: false
-  gem "pronto-rubocop", "0.9.1",  require: false
-  gem "rubocop",        "0.57.2", require: false
+  gem "pronto",         "0.10.0",  require: false
+  gem "pronto-rubocop", "0.10.0",  require: false
+  gem "rubocop",        "0.75.1", require: false
+  gem "rubocop-rails",  "2.3.2",  require: false
 
   # automatic test runs
   gem "guard-rspec",   require: false
@@ -40,16 +43,16 @@ end
 
 group :test do
   # rspec formatter
-  gem "fuubar", "2.3.2",    require: false
+  gem "fuubar", "2.4.1",    require: false
   gem "nyan-cat-formatter", require: false
 
   # test coverage
-  gem "simplecov",                 "0.16.1",   require: false
+  gem "simplecov",                 "0.17.1",   require: false
   gem "simplecov-rcov",            "0.2.3",    require: false
 
   # test helpers
   gem "json-schema-rspec", "0.0.4"
-  gem "rspec-collection_matchers", "~> 1.1.2"
+  gem "rspec-collection_matchers", "~> 1.2.0"
   gem "rspec-json_expectations",   "~> 2.1"
   gem "webmock",                   "~> 3.0"
 end
@@ -58,6 +61,6 @@ group :development, :test do
   gem "rake"
 
   # unit tests
-  gem "rspec", "~> 3.8.0"
-  gem "rspec-rails", "~> 3.8.0"
+  gem "rspec", "~> 3.9.0"
+  gem "rspec-rails", "~> 3.9.0"
 end
diff --git a/Gemfile.lock b/Gemfile.lock
index 9ebdd4b..f729fb3 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -2,14 +2,14 @@ PATH
   remote: .
   specs:
     diaspora_federation (0.2.6)
-      faraday (>= 0.9.0, < 0.16.0)
+      faraday (>= 0.9.0, < 0.18.0)
       faraday_middleware (>= 0.10.0, < 0.14.0)
       nokogiri (~> 1.6, >= 1.6.8)
       typhoeus (~> 1.0)
       valid (~> 1.0)
     diaspora_federation-json_schema (0.2.6)
     diaspora_federation-rails (0.2.6)
-      actionpack (>= 4.2, < 6)
+      actionpack (>= 5, < 7)
       diaspora_federation (= 0.2.6)
     diaspora_federation-test (0.2.6)
       diaspora_federation (= 0.2.6)
@@ -19,26 +19,27 @@ PATH
 GEM
   remote: https://rubygems.org/
   specs:
-    actionpack (5.2.2.1)
-      actionview (= 5.2.2.1)
-      activesupport (= 5.2.2.1)
+    actionpack (6.0.0)
+      actionview (= 6.0.0)
+      activesupport (= 6.0.0)
       rack (~> 2.0)
       rack-test (>= 0.6.3)
       rails-dom-testing (~> 2.0)
-      rails-html-sanitizer (~> 1.0, >= 1.0.2)
-    actionview (5.2.2.1)
-      activesupport (= 5.2.2.1)
+      rails-html-sanitizer (~> 1.0, >= 1.2.0)
+    actionview (6.0.0)
+      activesupport (= 6.0.0)
       builder (~> 3.1)
       erubi (~> 1.4)
       rails-dom-testing (~> 2.0)
-      rails-html-sanitizer (~> 1.0, >= 1.0.3)
-    activesupport (5.2.2.1)
+      rails-html-sanitizer (~> 1.1, >= 1.2.0)
+    activesupport (6.0.0)
       concurrent-ruby (~> 1.0, >= 1.0.2)
       i18n (>= 0.7, < 2)
       minitest (~> 5.1)
       tzinfo (~> 1.1)
-    addressable (2.5.2)
-      public_suffix (>= 2.0.2, < 4.0)
+      zeitwerk (~> 2.1, >= 2.1.8)
+    addressable (2.7.0)
+      public_suffix (>= 2.0.2, < 5.0)
     ast (2.4.0)
     builder (3.2.3)
     byebug (11.0.1)
@@ -46,26 +47,26 @@ GEM
     concurrent-ruby (1.1.5)
     crack (0.4.3)
       safe_yaml (~> 1.0.0)
-    crass (1.0.4)
+    crass (1.0.5)
     diff-lcs (1.3)
-    docile (1.3.1)
-    erubi (1.8.0)
+    docile (1.3.2)
+    erubi (1.9.0)
     ethon (0.12.0)
       ffi (>= 1.3.0)
-    fabrication (2.20.1)
-    faraday (0.15.4)
+    fabrication (2.20.2)
+    faraday (0.17.0)
       multipart-post (>= 1.2, < 3)
     faraday_middleware (0.13.1)
       faraday (>= 0.7.4, < 1.0)
-    ffi (1.10.0)
+    ffi (1.11.1)
     formatador (0.2.5)
-    fuubar (2.3.2)
+    fuubar (2.4.1)
       rspec-core (~> 3.0)
       ruby-progressbar (~> 1.4)
-    gitlab (4.10.0)
+    gitlab (4.12.0)
       httparty (~> 0.14, >= 0.14.0)
       terminal-table (~> 1.5, >= 1.5.1)
-    guard (2.15.0)
+    guard (2.15.1)
       formatador (>= 0.2.4)
       listen (>= 2.7, < 4.0)
       lumberjack (>= 1.0.12, < 2.0)
@@ -82,60 +83,58 @@ GEM
     guard-rubocop (1.3.0)
       guard (~> 2.0)
       rubocop (~> 0.20)
-    hashdiff (0.3.8)
-    httparty (0.16.4)
+    hashdiff (1.0.0)
+    httparty (0.17.1)
       mime-types (~> 3.0)
       multi_xml (>= 0.5.2)
-    i18n (1.4.0)
+    i18n (1.7.0)
       concurrent-ruby (~> 1.0)
-    jaro_winkler (1.5.2)
+    jaro_winkler (1.5.3)
     json (2.2.0)
     json-schema (2.8.1)
       addressable (>= 2.4)
     json-schema-rspec (0.0.4)
       json-schema (~> 2.5)
       rspec
-    listen (3.1.5)
-      rb-fsevent (~> 0.9, >= 0.9.4)
-      rb-inotify (~> 0.9, >= 0.9.7)
-      ruby_dep (~> 1.2)
-    loofah (2.2.3)
+    listen (3.2.0)
+      rb-fsevent (~> 0.10, >= 0.10.3)
+      rb-inotify (~> 0.9, >= 0.9.10)
+    loofah (2.3.0)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
     lumberjack (1.0.13)
-    macaddr (1.7.1)
-      systemu (~> 2.6.2)
+    macaddr (1.7.2)
+      systemu (~> 2.6.5)
     method_source (0.9.2)
-    mime-types (3.2.2)
+    mime-types (3.3)
       mime-types-data (~> 3.2015)
-    mime-types-data (3.2018.0812)
+    mime-types-data (3.2019.1009)
     mini_portile2 (2.4.0)
-    minitest (5.11.3)
+    minitest (5.12.2)
     multi_xml (0.6.0)
-    multipart-post (2.0.0)
+    multipart-post (2.1.1)
     nenv (0.3.0)
-    nokogiri (1.9.1)
+    nokogiri (1.10.4)
       mini_portile2 (~> 2.4.0)
-    notiffany (0.1.1)
+    notiffany (0.1.3)
       nenv (~> 0.1)
       shellany (~> 0.0)
     nyan-cat-formatter (0.12.0)
       rspec (>= 2.99, >= 2.14.2, < 4)
-    octokit (4.13.0)
+    octokit (4.14.0)
       sawyer (~> 0.8.0, >= 0.5.3)
-    parallel (1.14.0)
-    parser (2.6.2.0)
+    parallel (1.18.0)
+    parser (2.6.5.0)
       ast (~> 2.4.0)
-    powerpack (0.1.2)
-    pronto (0.9.5)
+    pronto (0.10.0)
       gitlab (~> 4.0, >= 4.0.0)
       httparty (>= 0.13.7)
       octokit (~> 4.7, >= 4.7.0)
-      rainbow (~> 2.1)
+      rainbow (>= 2.2, < 4.0)
       rugged (~> 0.24, >= 0.23.0)
-      thor (~> 0.19.0)
-    pronto-rubocop (0.9.1)
-      pronto (~> 0.9.0)
+      thor (~> 0.20.0)
+    pronto-rubocop (0.10.0)
+      pronto (~> 0.10.0)
       rubocop (~> 0.50, >= 0.49.1)
     pry (0.12.2)
       coderay (~> 1.1.0)
@@ -143,76 +142,75 @@ GEM
     pry-byebug (3.7.0)
       byebug (~> 11.0)
       pry (~> 0.10)
-    public_suffix (3.0.3)
-    rack (2.0.6)
+    public_suffix (4.0.1)
+    rack (2.0.7)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
     rails-dom-testing (2.0.3)
       activesupport (>= 4.2.0)
       nokogiri (>= 1.6)
-    rails-html-sanitizer (1.0.4)
-      loofah (~> 2.2, >= 2.2.2)
-    railties (5.2.2.1)
-      actionpack (= 5.2.2.1)
-      activesupport (= 5.2.2.1)
+    rails-html-sanitizer (1.3.0)
+      loofah (~> 2.3)
+    railties (6.0.0)
+      actionpack (= 6.0.0)
+      activesupport (= 6.0.0)
       method_source
       rake (>= 0.8.7)
-      thor (>= 0.19.0, < 2.0)
-    rainbow (2.2.2)
-      rake
-    rake (12.3.2)
+      thor (>= 0.20.3, < 2.0)
+    rainbow (3.0.0)
+    rake (13.0.0)
     rb-fsevent (0.10.3)
     rb-inotify (0.10.0)
       ffi (~> 1.0)
-    rspec (3.8.0)
-      rspec-core (~> 3.8.0)
-      rspec-expectations (~> 3.8.0)
-      rspec-mocks (~> 3.8.0)
-    rspec-collection_matchers (1.1.3)
+    rspec (3.9.0)
+      rspec-core (~> 3.9.0)
+      rspec-expectations (~> 3.9.0)
+      rspec-mocks (~> 3.9.0)
+    rspec-collection_matchers (1.2.0)
       rspec-expectations (>= 2.99.0.beta1)
-    rspec-core (3.8.0)
-      rspec-support (~> 3.8.0)
-    rspec-expectations (3.8.2)
+    rspec-core (3.9.0)
+      rspec-support (~> 3.9.0)
+    rspec-expectations (3.9.0)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.8.0)
-    rspec-json_expectations (2.1.0)
-    rspec-mocks (3.8.0)
+      rspec-support (~> 3.9.0)
+    rspec-json_expectations (2.2.0)
+    rspec-mocks (3.9.0)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.8.0)
-    rspec-rails (3.8.2)
+      rspec-support (~> 3.9.0)
+    rspec-rails (3.9.0)
       actionpack (>= 3.0)
       activesupport (>= 3.0)
       railties (>= 3.0)
-      rspec-core (~> 3.8.0)
-      rspec-expectations (~> 3.8.0)
-      rspec-mocks (~> 3.8.0)
-      rspec-support (~> 3.8.0)
-    rspec-support (3.8.0)
-    rubocop (0.57.2)
+      rspec-core (~> 3.9.0)
+      rspec-expectations (~> 3.9.0)
+      rspec-mocks (~> 3.9.0)
+      rspec-support (~> 3.9.0)
+    rspec-support (3.9.0)
+    rubocop (0.75.1)
       jaro_winkler (~> 1.5.1)
       parallel (~> 1.10)
-      parser (>= 2.5)
-      powerpack (~> 0.1)
+      parser (>= 2.6)
       rainbow (>= 2.2.2, < 4.0)
       ruby-progressbar (~> 1.7)
-      unicode-display_width (~> 1.0, >= 1.0.1)
-    ruby-progressbar (1.10.0)
-    ruby_dep (1.5.0)
-    rugged (0.28.1)
+      unicode-display_width (>= 1.4.0, < 1.7)
+    rubocop-rails (2.3.2)
+      rack (>= 1.1)
+      rubocop (>= 0.72.0)
+    ruby-progressbar (1.10.1)
+    rugged (0.28.3.1)
     safe_yaml (1.0.5)
-    sawyer (0.8.1)
-      addressable (>= 2.3.5, < 2.6)
-      faraday (~> 0.8, < 1.0)
+    sawyer (0.8.2)
+      addressable (>= 2.3.5)
+      faraday (> 0.8, < 2.0)
     shellany (0.0.1)
-    simplecov (0.16.1)
+    simplecov (0.17.1)
       docile (~> 1.1)
       json (>= 1.8, < 3)
       simplecov-html (~> 0.10.0)
     simplecov-html (0.10.2)
     simplecov-rcov (0.2.3)
       simplecov (>= 0.4.1)
-    spring (2.0.2)
-      activesupport (>= 4.2)
+    spring (2.1.0)
     spring-commands-rspec (1.0.4)
       spring (>= 0.9.1)
     spring-watcher-listen (2.0.1)
@@ -221,21 +219,22 @@ GEM
     systemu (2.6.5)
     terminal-table (1.8.0)
       unicode-display_width (~> 1.1, >= 1.1.1)
-    thor (0.19.4)
+    thor (0.20.3)
     thread_safe (0.3.6)
     typhoeus (1.3.1)
       ethon (>= 0.9.0)
     tzinfo (1.2.5)
       thread_safe (~> 0.1)
-    unicode-display_width (1.5.0)
+    unicode-display_width (1.6.0)
     uuid (2.3.9)
       macaddr (~> 1.0)
     valid (1.2.0)
-    webmock (3.5.1)
+    webmock (3.7.6)
       addressable (>= 2.3.6)
       crack (>= 0.3.2)
-      hashdiff
+      hashdiff (>= 0.4.0, < 2.0.0)
     yard (0.9.20)
+    zeitwerk (2.2.0)
 
 PLATFORMS
   ruby
@@ -245,22 +244,23 @@ DEPENDENCIES
   diaspora_federation-json_schema!
   diaspora_federation-rails!
   diaspora_federation-test!
-  fuubar (= 2.3.2)
+  fuubar (= 2.4.1)
   guard-rspec
   guard-rubocop
   json-schema-rspec (= 0.0.4)
   nyan-cat-formatter
-  pronto (= 0.9.5)
-  pronto-rubocop (= 0.9.1)
+  pronto (= 0.10.0)
+  pronto-rubocop (= 0.10.0)
   pry
   pry-byebug
   rake
-  rspec (~> 3.8.0)
-  rspec-collection_matchers (~> 1.1.2)
+  rspec (~> 3.9.0)
+  rspec-collection_matchers (~> 1.2.0)
   rspec-json_expectations (~> 2.1)
-  rspec-rails (~> 3.8.0)
-  rubocop (= 0.57.2)
-  simplecov (= 0.16.1)
+  rspec-rails (~> 3.9.0)
+  rubocop (= 0.75.1)
+  rubocop-rails (= 2.3.2)
+  simplecov (= 0.17.1)
   simplecov-rcov (= 0.2.3)
   spring
   spring-commands-rspec
@@ -269,4 +269,4 @@ DEPENDENCIES
   yard
 
 BUNDLED WITH
-   1.17.3
+   2.0.2
diff --git a/Guardfile b/Guardfile
index ef40b68..d0f3e68 100644
--- a/Guardfile
+++ b/Guardfile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 guard :rspec, cmd: "NO_COVERAGE=true bin/rspec" do
   require "guard/rspec/dsl"
   dsl = Guard::RSpec::Dsl.new(self)
diff --git a/Rakefile b/Rakefile
index ad80011..a3a1bb9 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 begin
   require "bundler/setup"
 rescue LoadError
diff --git a/app/controllers/diaspora_federation/application_controller.rb b/app/controllers/diaspora_federation/application_controller.rb
index 820394f..47eefd3 100644
--- a/app/controllers/diaspora_federation/application_controller.rb
+++ b/app/controllers/diaspora_federation/application_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   # Base controller for all DiasporaFederation controllers
   class ApplicationController < ActionController::Base
diff --git a/app/controllers/diaspora_federation/fetch_controller.rb b/app/controllers/diaspora_federation/fetch_controller.rb
index de5d651..24ec5fd 100644
--- a/app/controllers/diaspora_federation/fetch_controller.rb
+++ b/app/controllers/diaspora_federation/fetch_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_dependency "diaspora_federation/application_controller"
 
 module DiasporaFederation
diff --git a/app/controllers/diaspora_federation/h_card_controller.rb b/app/controllers/diaspora_federation/h_card_controller.rb
index b7d2f2e..b7af1f8 100644
--- a/app/controllers/diaspora_federation/h_card_controller.rb
+++ b/app/controllers/diaspora_federation/h_card_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_dependency "diaspora_federation/application_controller"
 
 module DiasporaFederation
diff --git a/app/controllers/diaspora_federation/receive_controller.rb b/app/controllers/diaspora_federation/receive_controller.rb
index 9155a8a..a477dfd 100644
--- a/app/controllers/diaspora_federation/receive_controller.rb
+++ b/app/controllers/diaspora_federation/receive_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_dependency "diaspora_federation/application_controller"
 
 module DiasporaFederation
diff --git a/app/controllers/diaspora_federation/webfinger_controller.rb b/app/controllers/diaspora_federation/webfinger_controller.rb
index 542eb8f..da275de 100644
--- a/app/controllers/diaspora_federation/webfinger_controller.rb
+++ b/app/controllers/diaspora_federation/webfinger_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require_dependency "diaspora_federation/application_controller"
 
 module DiasporaFederation
diff --git a/config/initializers/filter_parameter_logging.rb b/config/initializers/filter_parameter_logging.rb
index 67516e1..4a8838c 100644
--- a/config/initializers/filter_parameter_logging.rb
+++ b/config/initializers/filter_parameter_logging.rb
@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 # Don't log received xml data.
 Rails.application.config.filter_parameters += %i[xml aes_key encrypted_magic_envelope]
diff --git a/config/initializers/mime_types.rb b/config/initializers/mime_types.rb
index 10cadb2..27cecfb 100644
--- a/config/initializers/mime_types.rb
+++ b/config/initializers/mime_types.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # mime types for webfinger
 Mime::Type.register "application/jrd+json", :jrd
 Mime::Type.register "application/xrd+xml", :xrd
diff --git a/config/routes.rb b/config/routes.rb
index 30c1a98..2c34046 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 DiasporaFederation::Engine.routes.draw do
   controller :receive do
     post "receive/public"      => :public,  :as => "receive_public"
diff --git a/config/spring.rb b/config/spring.rb
index d8a7f92..69680fe 100644
--- a/config/spring.rb
+++ b/config/spring.rb
@@ -1,6 +1,11 @@
+# frozen_string_literal: true
+
 Spring.application_root = "./test/dummy"
 
 root_path = Pathname.new(File.expand_path("."))
 Spring.watcher = Spring::Watcher::Listen.new(root_path, 0.2)
 
-Spring.watch("./lib/")
+Spring.watch(
+  "./lib/",
+  ".ruby-version"
+)
diff --git a/diaspora_federation-json_schema.gemspec b/diaspora_federation-json_schema.gemspec
index d078a28..5cae269 100644
--- a/diaspora_federation-json_schema.gemspec
+++ b/diaspora_federation-json_schema.gemspec
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 $LOAD_PATH.push File.expand_path("lib", __dir__)
 
 # Maintain your gem's version:
diff --git a/diaspora_federation-rails.gemspec b/diaspora_federation-rails.gemspec
index edc4fba..625372d 100644
--- a/diaspora_federation-rails.gemspec
+++ b/diaspora_federation-rails.gemspec
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 $LOAD_PATH.push File.expand_path("lib", __dir__)
 
 # Maintain your gem's version:
@@ -17,9 +19,9 @@ Gem::Specification.new do |s|
   s.files       = Dir["app/**/*", "config/routes.rb", "config/initializers/*",
                       "lib/diaspora_federation/{engine,rails}.rb", "LICENSE", "README.md", "Changelog.md"]
 
-  s.required_ruby_version = "~> 2.1"
+  s.required_ruby_version = "~> 2.5"
 
-  s.add_dependency "actionpack", ">= 4.2", "< 6"
+  s.add_dependency "actionpack", ">= 5", "< 7"
 
   s.add_dependency "diaspora_federation", DiasporaFederation::VERSION
 end
diff --git a/diaspora_federation-test.gemspec b/diaspora_federation-test.gemspec
index b37a076..40a0da8 100644
--- a/diaspora_federation-test.gemspec
+++ b/diaspora_federation-test.gemspec
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 $LOAD_PATH.push File.expand_path("lib", __dir__)
 
 # Maintain your gem's version:
@@ -17,7 +19,7 @@ Gem::Specification.new do |s|
 
   s.files       = Dir["lib/diaspora_federation/test.rb", "lib/diaspora_federation/test/*"]
 
-  s.required_ruby_version = "~> 2.1"
+  s.required_ruby_version = "~> 2.5"
 
   s.add_dependency "diaspora_federation", DiasporaFederation::VERSION
   s.add_dependency "fabrication", "~> 2.16"
diff --git a/diaspora_federation.gemspec b/diaspora_federation.gemspec
index 447d0bb..0dd0723 100644
--- a/diaspora_federation.gemspec
+++ b/diaspora_federation.gemspec
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 $LOAD_PATH.push File.expand_path("lib", __dir__)
 
 # Maintain your gem's version:
@@ -22,9 +24,9 @@ Gem::Specification.new do |s|
                         "lib/diaspora_federation/test/*",
                         "lib/tasks/*.rake"]
 
-  s.required_ruby_version = "~> 2.1"
+  s.required_ruby_version = "~> 2.5"
 
-  s.add_dependency "faraday", ">= 0.9.0", "< 0.16.0"
+  s.add_dependency "faraday", ">= 0.9.0", "< 0.18.0"
   s.add_dependency "faraday_middleware", ">= 0.10.0", "< 0.14.0"
   s.add_dependency "nokogiri", "~> 1.6", ">= 1.6.8"
   s.add_dependency "typhoeus", "~> 1.0"
diff --git a/lib/diaspora_federation.rb b/lib/diaspora_federation.rb
index 08c360a..ec2b036 100644
--- a/lib/diaspora_federation.rb
+++ b/lib/diaspora_federation.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "nokogiri"
 require "openssl"
 
@@ -256,6 +258,7 @@ module DiasporaFederation
       configuration_error "http_timeout: please configure a number" unless @http_timeout.is_a?(Integer)
 
       return unless !@http_verbose.is_a?(TrueClass) && !@http_verbose.is_a?(FalseClass)
+
       configuration_error "http_verbose: please configure a boolean"
     end
 
diff --git a/lib/diaspora_federation/callbacks.rb b/lib/diaspora_federation/callbacks.rb
index fae3689..c58fa34 100644
--- a/lib/diaspora_federation/callbacks.rb
+++ b/lib/diaspora_federation/callbacks.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   # Callbacks are used to communicate with the application. They are called to
   # fetch data and after data is received.
diff --git a/lib/diaspora_federation/discovery.rb b/lib/diaspora_federation/discovery.rb
index f4bd28d..ab587c9 100644
--- a/lib/diaspora_federation/discovery.rb
+++ b/lib/diaspora_federation/discovery.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   # This module provides the namespace for the various classes implementing
   # WebFinger and other protocols used for metadata discovery on remote servers
diff --git a/lib/diaspora_federation/discovery/discovery.rb b/lib/diaspora_federation/discovery/discovery.rb
index 5f24513..23f2ea0 100644
--- a/lib/diaspora_federation/discovery/discovery.rb
+++ b/lib/diaspora_federation/discovery/discovery.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Discovery
     # This class contains the logic to fetch all data for the given diaspora* ID.
@@ -35,6 +37,7 @@ module DiasporaFederation
       def validate_diaspora_id
         # Validates if the diaspora* ID matches the diaspora* ID in the webfinger response
         return if diaspora_id == clean_diaspora_id(webfinger.acct_uri)
+
         raise DiscoveryError, "diaspora* ID does not match: Wanted #{diaspora_id} but got" \
                               " #{clean_diaspora_id(webfinger.acct_uri)}"
       end
@@ -47,15 +50,13 @@ module DiasporaFederation
         logger.info "Fetching #{url} for #{diaspora_id}"
         response = HttpClient.get(url)
         raise "Failed to fetch #{url}: #{response.status}" unless response.success?
+
         response.body
       rescue => e # rubocop:disable Style/RescueStandardError
-        unless http_fallback && url.start_with?("https://")
-          raise DiscoveryError, "Failed to fetch #{url} for #{diaspora_id}: #{e.class}: #{e.message}"
-        end
+        raise DiscoveryError, "Failed to fetch #{url} for #{diaspora_id}: #{e.class}: #{e.message}" unless http_fallback
 
         logger.warn "Retry with http: #{url} for #{diaspora_id}: #{e.class}: #{e.message}"
-        url.sub!("https://", "http://")
-        retry
+        get(url.sub("https://", "http://"))
       end
 
       def domain
@@ -74,6 +75,7 @@ module DiasporaFederation
 
       def webfinger
         return @webfinger if @webfinger
+
         webfinger_url = "https://#{domain}/.well-known/webfinger?resource=#{acct_parameter}"
 
         # This tries the WebFinger URL with https first, then falls back to http if webfinger_http_fallback is enabled.
diff --git a/lib/diaspora_federation/discovery/exceptions.rb b/lib/diaspora_federation/discovery/exceptions.rb
index caba207..3985b5b 100644
--- a/lib/diaspora_federation/discovery/exceptions.rb
+++ b/lib/diaspora_federation/discovery/exceptions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Discovery
     # Raised, if there is an error while discover a new person
diff --git a/lib/diaspora_federation/discovery/h_card.rb b/lib/diaspora_federation/discovery/h_card.rb
index 69d7526..562979a 100644
--- a/lib/diaspora_federation/discovery/h_card.rb
+++ b/lib/diaspora_federation/discovery/h_card.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Discovery
     # This class provides the means of generating and parsing account data to and
@@ -260,6 +262,7 @@ module DiasporaFederation
 
         doc = Nokogiri::HTML::Document.parse(html_string)
         raise InvalidData, "hcard html incomplete" unless html_document_complete?(doc)
+
         doc
       end
 
diff --git a/lib/diaspora_federation/discovery/host_meta.rb b/lib/diaspora_federation/discovery/host_meta.rb
index b7a8b95..cc15da0 100644
--- a/lib/diaspora_federation/discovery/host_meta.rb
+++ b/lib/diaspora_federation/discovery/host_meta.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Discovery
     # Generates and parses Host Meta documents.
@@ -25,7 +27,7 @@ module DiasporaFederation
       end
 
       # URL fragment to append to the base URL
-      WEBFINGER_SUFFIX = "/.well-known/webfinger.xml?resource={uri}".freeze
+      WEBFINGER_SUFFIX = "/.well-known/webfinger.xml?resource={uri}"
 
       # Returns the WebFinger URL that was used to build this instance (either from
       # xml or by giving a base URL).
diff --git a/lib/diaspora_federation/discovery/web_finger.rb b/lib/diaspora_federation/discovery/web_finger.rb
index 295038e..b56fb9c 100644
--- a/lib/diaspora_federation/discovery/web_finger.rb
+++ b/lib/diaspora_federation/discovery/web_finger.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Discovery
     # The WebFinger document used for diaspora* user discovery is based on an
@@ -69,23 +71,23 @@ module DiasporaFederation
       property :subscribe_url, :string, optional: true
 
       # +hcard_url+ link relation
-      REL_HCARD = "http://microformats.org/profile/hcard".freeze
+      REL_HCARD = "http://microformats.org/profile/hcard"
 
       # +seed_url+ link relation
-      REL_SEED = "http://joindiaspora.com/seed_location".freeze
+      REL_SEED = "http://joindiaspora.com/seed_location"
 
       # +profile_url+ link relation.
       # @note This might just as well be an +Alias+ instead of a +Link+.
-      REL_PROFILE = "http://webfinger.net/rel/profile-page".freeze
+      REL_PROFILE = "http://webfinger.net/rel/profile-page"
 
       # +atom_url+ link relation
-      REL_ATOM = "http://schemas.google.com/g/2010#updates-from".freeze
+      REL_ATOM = "http://schemas.google.com/g/2010#updates-from"
 
       # +salmon_url+ link relation
-      REL_SALMON = "salmon".freeze
+      REL_SALMON = "salmon"
 
       # +subscribe_url+ link relation
-      REL_SUBSCRIBE = "http://ostatus.org/schema/1.0/subscribe".freeze
+      REL_SUBSCRIBE = "http://ostatus.org/schema/1.0/subscribe"
 
       # Additional WebFinger data
       # @return [Hash] additional elements
@@ -110,7 +112,7 @@ module DiasporaFederation
         to_xrd.to_xml
       end
 
-      def to_json
+      def to_json(*_args)
         to_xrd.to_json
       end
 
diff --git a/lib/diaspora_federation/discovery/xrd_document.rb b/lib/diaspora_federation/discovery/xrd_document.rb
index 354594c..6a3bb21 100644
--- a/lib/diaspora_federation/discovery/xrd_document.rb
+++ b/lib/diaspora_federation/discovery/xrd_document.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Discovery
     # This class implements basic handling of XRD documents as far as it is
@@ -29,13 +31,13 @@ module DiasporaFederation
     # @see http://docs.oasis-open.org/xri/xrd/v1.0/xrd-1.0.html Extensible Resource Descriptor (XRD) Version 1.0
     class XrdDocument
       # xml namespace url
-      XMLNS = "http://docs.oasis-open.org/ns/xri/xrd-1.0".freeze
+      XMLNS = "http://docs.oasis-open.org/ns/xri/xrd-1.0"
 
       # +Link+ element attributes
       LINK_ATTRS = %i[rel type href template].freeze
 
       # format string for datetime (+Expires+ element)
-      DATETIME_FORMAT = "%Y-%m-%dT%H:%M:%SZ".freeze
+      DATETIME_FORMAT = "%Y-%m-%dT%H:%M:%SZ"
 
       # The <Expires> element contains a time value which specifies the instant at
       # and after which the document has expired and SHOULD NOT be used.
@@ -80,7 +82,7 @@ module DiasporaFederation
         }.to_xml
       end
 
-      def to_json
+      def to_json(*_args)
         {
           subject:    subject,
           expires:    (expires.strftime(DATETIME_FORMAT) if expires.instance_of?(DateTime)),
@@ -146,6 +148,7 @@ module DiasporaFederation
       def add_aliases_to(xml)
         aliases.each do |a|
           next if !a.instance_of?(String) || a.empty?
+
           xml.Alias(a.to_s)
         end
       end
@@ -171,6 +174,7 @@ module DiasporaFederation
 
         doc = Nokogiri::XML(xrd_doc)
         raise InvalidDocument, "Not an XRD document" if !doc.root || doc.root.name != "XRD"
+
         doc
       end
 
diff --git a/lib/diaspora_federation/engine.rb b/lib/diaspora_federation/engine.rb
index 0941467..3ab91df 100644
--- a/lib/diaspora_federation/engine.rb
+++ b/lib/diaspora_federation/engine.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   # diaspora* federation rails engine
   class Engine < ::Rails::Engine
diff --git a/lib/diaspora_federation/entities.rb b/lib/diaspora_federation/entities.rb
index a7689d0..d29388b 100644
--- a/lib/diaspora_federation/entities.rb
+++ b/lib/diaspora_federation/entities.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   # This namespace contains all the entities used to encapsulate data that is
   # passed around in the diaspora* network as part of the federation protocol.
diff --git a/lib/diaspora_federation/entities/account_deletion.rb b/lib/diaspora_federation/entities/account_deletion.rb
index 88e087e..d969b24 100644
--- a/lib/diaspora_federation/entities/account_deletion.rb
+++ b/lib/diaspora_federation/entities/account_deletion.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # This entity is sent when an account was deleted on a remote pod.
diff --git a/lib/diaspora_federation/entities/account_migration.rb b/lib/diaspora_federation/entities/account_migration.rb
index 82deed3..7ea7ef8 100644
--- a/lib/diaspora_federation/entities/account_migration.rb
+++ b/lib/diaspora_federation/entities/account_migration.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # This entity is sent when a person changes their diaspora* ID (e.g. when a user migration
@@ -37,13 +39,14 @@ module DiasporaFederation
       # @return [String] diaspora* ID of the old person identity
       def old_identity
         return @old_identity if author_is_new_id?
+
         author
       end
 
       # Returns diaspora* ID of the new person identity.
       # @return [String] diaspora* ID of the new person identity
       def new_identity
-        profile.author if profile
+        profile&.author
       end
 
       # @return [String] string representation of this object
@@ -85,6 +88,7 @@ module DiasporaFederation
       def sign_with_respective_key
         privkey = DiasporaFederation.callbacks.trigger(:fetch_private_key, signer_id)
         raise PrivateKeyNotFound, "signer=#{signer_id} obj=#{self}" if privkey.nil?
+
         sign_with_key(privkey).tap do
           logger.info "event=sign status=complete signature=signature signer=#{signer_id} obj=#{self}"
         end
diff --git a/lib/diaspora_federation/entities/account_migration/signable.rb b/lib/diaspora_federation/entities/account_migration/signable.rb
index 40cb5f1..fe8825d 100644
--- a/lib/diaspora_federation/entities/account_migration/signable.rb
+++ b/lib/diaspora_federation/entities/account_migration/signable.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     class AccountMigration < Entity
diff --git a/lib/diaspora_federation/entities/comment.rb b/lib/diaspora_federation/entities/comment.rb
index b3f05e7..f271b1d 100644
--- a/lib/diaspora_federation/entities/comment.rb
+++ b/lib/diaspora_federation/entities/comment.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # This entity represents a comment to some kind of post (e.g. status message).
@@ -5,7 +7,7 @@ module DiasporaFederation
     # @see Validators::CommentValidator
     class Comment < Entity
       # The {Comment} parent is a {Post}
-      PARENT_TYPE = "Post".freeze
+      PARENT_TYPE = "Post"
 
       include Relayable
 
diff --git a/lib/diaspora_federation/entities/contact.rb b/lib/diaspora_federation/entities/contact.rb
index bd5c0f2..52e8d0e 100644
--- a/lib/diaspora_federation/entities/contact.rb
+++ b/lib/diaspora_federation/entities/contact.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # This entity represents a contact with another person. A user issues it
diff --git a/lib/diaspora_federation/entities/conversation.rb b/lib/diaspora_federation/entities/conversation.rb
index 57898d0..b3720d3 100644
--- a/lib/diaspora_federation/entities/conversation.rb
+++ b/lib/diaspora_federation/entities/conversation.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # This entity represents a private conversation between users.
diff --git a/lib/diaspora_federation/entities/embed.rb b/lib/diaspora_federation/entities/embed.rb
index 166b99a..76136f5 100644
--- a/lib/diaspora_federation/entities/embed.rb
+++ b/lib/diaspora_federation/entities/embed.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # This entity is used to specify embed information about an URL that should be embedded.
diff --git a/lib/diaspora_federation/entities/event.rb b/lib/diaspora_federation/entities/event.rb
index 274c1e3..02ddba7 100644
--- a/lib/diaspora_federation/entities/event.rb
+++ b/lib/diaspora_federation/entities/event.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # This entity represents an event and it is federated as a part of a status message.
diff --git a/lib/diaspora_federation/entities/event_participation.rb b/lib/diaspora_federation/entities/event_participation.rb
index 1dfa504..fd1eaac 100644
--- a/lib/diaspora_federation/entities/event_participation.rb
+++ b/lib/diaspora_federation/entities/event_participation.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # This entity represents a participation in an event, i.e. it is issued when a user responds to en event.
@@ -5,7 +7,7 @@ module DiasporaFederation
     # @see Validators::EventParticipationValidator
     class EventParticipation < Entity
       # The {EventParticipation} parent is an {Event}
-      PARENT_TYPE = "Event".freeze
+      PARENT_TYPE = "Event"
 
       include Relayable
 
diff --git a/lib/diaspora_federation/entities/like.rb b/lib/diaspora_federation/entities/like.rb
index b1b7b2e..b589058 100644
--- a/lib/diaspora_federation/entities/like.rb
+++ b/lib/diaspora_federation/entities/like.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # This entity represents a like to some kind of post (e.g. status message).
diff --git a/lib/diaspora_federation/entities/location.rb b/lib/diaspora_federation/entities/location.rb
index 5bd8501..3d0a134 100644
--- a/lib/diaspora_federation/entities/location.rb
+++ b/lib/diaspora_federation/entities/location.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # This entity is used to specify location data and used embedded in a status message.
diff --git a/lib/diaspora_federation/entities/message.rb b/lib/diaspora_federation/entities/message.rb
index c43b53b..81c631a 100644
--- a/lib/diaspora_federation/entities/message.rb
+++ b/lib/diaspora_federation/entities/message.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # This entity represents a private message exchanged in private conversation.
diff --git a/lib/diaspora_federation/entities/participation.rb b/lib/diaspora_federation/entities/participation.rb
index d0cc815..554d9bd 100644
--- a/lib/diaspora_federation/entities/participation.rb
+++ b/lib/diaspora_federation/entities/participation.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # Participation is sent to subscribe a user on updates for some post.
@@ -35,7 +37,7 @@ module DiasporaFederation
       # Validates that the parent exists and the parent author is local
       def validate_parent
         parent = DiasporaFederation.callbacks.trigger(:fetch_related_entity, parent_type, parent_guid)
-        raise ParentNotLocal, "obj=#{self}" unless parent && parent.local
+        raise ParentNotLocal, "obj=#{self}" unless parent&.local
       end
 
       # Validate that the parent is local.
diff --git a/lib/diaspora_federation/entities/person.rb b/lib/diaspora_federation/entities/person.rb
index ab48857..e4ad225 100644
--- a/lib/diaspora_federation/entities/person.rb
+++ b/lib/diaspora_federation/entities/person.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # This entity contains the base data of a person.
diff --git a/lib/diaspora_federation/entities/photo.rb b/lib/diaspora_federation/entities/photo.rb
index 0e60f31..4f11179 100644
--- a/lib/diaspora_federation/entities/photo.rb
+++ b/lib/diaspora_federation/entities/photo.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # This entity represents a photo and it is federated as a part of a status message.
diff --git a/lib/diaspora_federation/entities/poll.rb b/lib/diaspora_federation/entities/poll.rb
index 47fd2dc..6f3ba16 100644
--- a/lib/diaspora_federation/entities/poll.rb
+++ b/lib/diaspora_federation/entities/poll.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # This entity represents a poll and it is federated as an optional part of a status message.
diff --git a/lib/diaspora_federation/entities/poll_answer.rb b/lib/diaspora_federation/entities/poll_answer.rb
index 7c1ee17..2eb34dc 100644
--- a/lib/diaspora_federation/entities/poll_answer.rb
+++ b/lib/diaspora_federation/entities/poll_answer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # This entity represents a poll answer and is federated as a part of the Poll entity.
diff --git a/lib/diaspora_federation/entities/poll_participation.rb b/lib/diaspora_federation/entities/poll_participation.rb
index d1ce464..ec7eb86 100644
--- a/lib/diaspora_federation/entities/poll_participation.rb
+++ b/lib/diaspora_federation/entities/poll_participation.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # This entity represents a participation in poll, i.e. it is issued when a user votes for an answer in a poll.
@@ -5,7 +7,7 @@ module DiasporaFederation
     # @see Validators::PollParticipationValidator
     class PollParticipation < Entity
       # The {PollParticipation} parent is a {Poll}
-      PARENT_TYPE = "Poll".freeze
+      PARENT_TYPE = "Poll"
 
       include Relayable
 
diff --git a/lib/diaspora_federation/entities/post.rb b/lib/diaspora_federation/entities/post.rb
index 6957cdf..a5c0a48 100644
--- a/lib/diaspora_federation/entities/post.rb
+++ b/lib/diaspora_federation/entities/post.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # This is a module that defines common properties for a post which
diff --git a/lib/diaspora_federation/entities/profile.rb b/lib/diaspora_federation/entities/profile.rb
index ea851b1..b6ba0ff 100644
--- a/lib/diaspora_federation/entities/profile.rb
+++ b/lib/diaspora_federation/entities/profile.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # This entity contains all the profile data of a person.
diff --git a/lib/diaspora_federation/entities/related_entity.rb b/lib/diaspora_federation/entities/related_entity.rb
index b384748..4811cfd 100644
--- a/lib/diaspora_federation/entities/related_entity.rb
+++ b/lib/diaspora_federation/entities/related_entity.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # Entity meta informations for a related entity (parent or target of
@@ -50,7 +52,7 @@ module DiasporaFederation
       end
 
       # never add {RelatedEntity} to json
-      def to_json
+      def to_json(*_args)
         nil
       end
     end
diff --git a/lib/diaspora_federation/entities/relayable.rb b/lib/diaspora_federation/entities/relayable.rb
index 4ee3ffa..3fe94c8 100644
--- a/lib/diaspora_federation/entities/relayable.rb
+++ b/lib/diaspora_federation/entities/relayable.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # This is a module that defines common properties for relayable entities
@@ -88,7 +90,7 @@ module DiasporaFederation
         "#{super}#{":#{parent_type}" if respond_to?(:parent_type)}:#{parent_guid}"
       end
 
-      def to_json
+      def to_json(*_args)
         super.merge!(property_order: signature_order).tap {|json_hash|
           missing_properties = json_hash[:property_order] - json_hash[:entity_data].keys
           missing_properties.each {|property|
@@ -113,6 +115,7 @@ module DiasporaFederation
       def sign_with_author
         privkey = DiasporaFederation.callbacks.trigger(:fetch_private_key, author)
         raise AuthorPrivateKeyNotFound, "author=#{author} obj=#{self}" if privkey.nil?
+
         sign_with_key(privkey).tap do
           logger.info "event=sign status=complete signature=author_signature author=#{author} obj=#{self}"
         end
diff --git a/lib/diaspora_federation/entities/relayable_retraction.rb b/lib/diaspora_federation/entities/relayable_retraction.rb
index aa7b03f..d0365f1 100644
--- a/lib/diaspora_federation/entities/relayable_retraction.rb
+++ b/lib/diaspora_federation/entities/relayable_retraction.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # This entity represents a claim of deletion of a previously federated
diff --git a/lib/diaspora_federation/entities/request.rb b/lib/diaspora_federation/entities/request.rb
index a60aab1..6627f36 100644
--- a/lib/diaspora_federation/entities/request.rb
+++ b/lib/diaspora_federation/entities/request.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # This entity represents a sharing request for a user. A user issues it
diff --git a/lib/diaspora_federation/entities/reshare.rb b/lib/diaspora_federation/entities/reshare.rb
index 7c0bcc6..aa38b29 100644
--- a/lib/diaspora_federation/entities/reshare.rb
+++ b/lib/diaspora_federation/entities/reshare.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # This entity represents the fact that a user reshared another user's post.
diff --git a/lib/diaspora_federation/entities/retraction.rb b/lib/diaspora_federation/entities/retraction.rb
index 217c0a6..5c53eda 100644
--- a/lib/diaspora_federation/entities/retraction.rb
+++ b/lib/diaspora_federation/entities/retraction.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # This entity represents a claim of deletion of a previously federated entity.
@@ -28,7 +30,7 @@ module DiasporaFederation
       def sender_valid?(sender)
         case target_type
         when "Comment", "Like", "PollParticipation"
-          sender == target.author || sender == target.root.author
+          [target.root.author, target.author].include?(sender)
         else
           sender == target.author
         end
diff --git a/lib/diaspora_federation/entities/signable.rb b/lib/diaspora_federation/entities/signable.rb
index d78d4a5..1301f17 100644
--- a/lib/diaspora_federation/entities/signable.rb
+++ b/lib/diaspora_federation/entities/signable.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # Signable is a module that encapsulates basic signature generation/verification flow for entities.
diff --git a/lib/diaspora_federation/entities/signed_retraction.rb b/lib/diaspora_federation/entities/signed_retraction.rb
index af850b9..77e474c 100644
--- a/lib/diaspora_federation/entities/signed_retraction.rb
+++ b/lib/diaspora_federation/entities/signed_retraction.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # This entity represents a claim of deletion of a previously federated
diff --git a/lib/diaspora_federation/entities/status_message.rb b/lib/diaspora_federation/entities/status_message.rb
index 6a50b61..1da0d8b 100644
--- a/lib/diaspora_federation/entities/status_message.rb
+++ b/lib/diaspora_federation/entities/status_message.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     # This entity represents a status message sent by a user.
diff --git a/lib/diaspora_federation/entity.rb b/lib/diaspora_federation/entity.rb
index 7b564be..26526d1 100644
--- a/lib/diaspora_federation/entity.rb
+++ b/lib/diaspora_federation/entity.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   # +Entity+ is the base class for all other objects used to encapsulate data
   # for federation messages in the diaspora* network.
@@ -38,10 +40,10 @@ module DiasporaFederation
 
     # Invalid XML characters
     # @see https://www.w3.org/TR/REC-xml/#charsets "Extensible Markup Language (XML) 1.0"
-    INVALID_XML_REGEX = /[^\x09\x0A\x0D\x20-\uD7FF\uE000-\uFFFD\u{10000}-\u{10FFFF}]/
+    INVALID_XML_REGEX = /[^\x09\x0A\x0D\x20-\uD7FF\uE000-\uFFFD\u{10000}-\u{10FFFF}]/.freeze
 
     # Regex to validate and find entity names
-    ENTITY_NAME_REGEX = "[a-z]*(?:_[a-z]*)*".freeze
+    ENTITY_NAME_REGEX = "[a-z]*(?:_[a-z]*)*"
 
     # Initializes the Entity with the given attribute hash and freezes the created
     # instance it returns.
@@ -149,6 +151,7 @@ module DiasporaFederation
     # @return [Class] entity class
     def self.entity_class(entity_name)
       raise InvalidEntityName, "'#{entity_name}' is invalid" unless entity_name =~ /\A#{ENTITY_NAME_REGEX}\z/
+
       class_name = entity_name.sub(/\A[a-z]/, &:upcase)
       class_name.gsub!(/_([a-z])/) { Regexp.last_match[1].upcase }
 
@@ -169,7 +172,7 @@ module DiasporaFederation
 
     # Renders entity to a hash representation of the entity JSON format
     # @return [Hash] Returns a hash that is equal by structure to the entity in JSON format
-    def to_json
+    def to_json(*_args)
       {
         entity_type: self.class.entity_name,
         entity_data: json_data
@@ -231,12 +234,14 @@ module DiasporaFederation
 
     def nilify(value)
       return nil if value.respond_to?(:empty?) && value.empty? && !value.instance_of?(Array)
+
       value
     end
 
     def instantiate_nested(name, value)
       if value.instance_of?(Array)
         return value unless value.first.instance_of?(Hash)
+
         value.map {|hash| self.class.class_props[name].first.new(hash) }
       elsif value.instance_of?(Hash)
         self.class.class_props[name].new(value)
diff --git a/lib/diaspora_federation/federation.rb b/lib/diaspora_federation/federation.rb
index b279cfd..e1ccd95 100644
--- a/lib/diaspora_federation/federation.rb
+++ b/lib/diaspora_federation/federation.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   # This module contains the federation logic
   module Federation
diff --git a/lib/diaspora_federation/federation/diaspora_url_parser.rb b/lib/diaspora_federation/federation/diaspora_url_parser.rb
index 5b59da2..d9ead05 100644
--- a/lib/diaspora_federation/federation/diaspora_url_parser.rb
+++ b/lib/diaspora_federation/federation/diaspora_url_parser.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Federation
     # This module is for parsing and fetching linked entities.
@@ -10,7 +12,7 @@ module DiasporaFederation
         (#{Validation::Rule::DiasporaId::DIASPORA_ID_REGEX})/
         (#{Entity::ENTITY_NAME_REGEX})/
         (#{Validation::Rule::Guid::VALID_CHARS})
-      }ux
+      }ux.freeze
 
       # Parses all diaspora:// URLs from the text and fetches the entities from
       # the remote server if needed.
@@ -25,6 +27,7 @@ module DiasporaFederation
       private_class_method def self.fetch_entity(author, type, guid)
         class_name = Entity.entity_class(type).to_s.rpartition("::").last
         return if DiasporaFederation.callbacks.trigger(:fetch_related_entity, class_name, guid)
+
         Fetcher.fetch_public(author, type, guid)
       rescue => e # rubocop:disable Style/RescueStandardError
         logger.error "Failed to fetch linked entity #{type}:#{guid}: #{e.class}: #{e.message}"
diff --git a/lib/diaspora_federation/federation/fetcher.rb b/lib/diaspora_federation/federation/fetcher.rb
index d9b85cf..b6a2136 100644
--- a/lib/diaspora_federation/federation/fetcher.rb
+++ b/lib/diaspora_federation/federation/fetcher.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Federation
     # This module is for fetching entities from other pods.
@@ -10,6 +12,7 @@ module DiasporaFederation
       def self.fetch_public(author, entity_type, guid)
         type = entity_name(entity_type).to_s
         raise "Already fetching ..." if fetching[type].include?(guid)
+
         fetch_from_url(author, type, guid)
       rescue => e # rubocop:disable Style/RescueStandardError
         raise NotFetchable, "Failed to fetch #{entity_type}:#{guid} from #{author}: #{e.class}: #{e.message}"
diff --git a/lib/diaspora_federation/federation/receiver.rb b/lib/diaspora_federation/federation/receiver.rb
index 76903e5..4b6eb76 100644
--- a/lib/diaspora_federation/federation/receiver.rb
+++ b/lib/diaspora_federation/federation/receiver.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Federation
     # This module parses and receives entities.
@@ -29,6 +31,7 @@ module DiasporaFederation
       # @param [Boolean] legacy use old slap parser
       def self.receive_private(data, recipient_private_key, recipient_id, legacy=false)
         raise ArgumentError, "no recipient key provided" unless recipient_private_key.instance_of?(OpenSSL::PKey::RSA)
+
         magic_env = if legacy
                       Salmon::EncryptedSlap.from_xml(data, recipient_private_key)
                     else
diff --git a/lib/diaspora_federation/federation/receiver/abstract_receiver.rb b/lib/diaspora_federation/federation/receiver/abstract_receiver.rb
index c244c1d..74b8abd 100644
--- a/lib/diaspora_federation/federation/receiver/abstract_receiver.rb
+++ b/lib/diaspora_federation/federation/receiver/abstract_receiver.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Federation
     module Receiver
diff --git a/lib/diaspora_federation/federation/receiver/exceptions.rb b/lib/diaspora_federation/federation/receiver/exceptions.rb
index 5c1a0b8..a48a20e 100644
--- a/lib/diaspora_federation/federation/receiver/exceptions.rb
+++ b/lib/diaspora_federation/federation/receiver/exceptions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Federation
     module Receiver
diff --git a/lib/diaspora_federation/federation/receiver/private.rb b/lib/diaspora_federation/federation/receiver/private.rb
index 18115cf..4267f9b 100644
--- a/lib/diaspora_federation/federation/receiver/private.rb
+++ b/lib/diaspora_federation/federation/receiver/private.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Federation
     module Receiver
@@ -7,6 +9,7 @@ module DiasporaFederation
 
         def validate
           raise RecipientRequired if recipient_id.nil?
+
           super
         end
       end
diff --git a/lib/diaspora_federation/federation/receiver/public.rb b/lib/diaspora_federation/federation/receiver/public.rb
index 7711088..d56611d 100644
--- a/lib/diaspora_federation/federation/receiver/public.rb
+++ b/lib/diaspora_federation/federation/receiver/public.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Federation
     module Receiver
diff --git a/lib/diaspora_federation/federation/sender.rb b/lib/diaspora_federation/federation/sender.rb
index ab15662..37f7a72 100644
--- a/lib/diaspora_federation/federation/sender.rb
+++ b/lib/diaspora_federation/federation/sender.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Federation
     # Federation logic to send messages to other pods
diff --git a/lib/diaspora_federation/federation/sender/hydra_wrapper.rb b/lib/diaspora_federation/federation/sender/hydra_wrapper.rb
index b300b07..df1adf1 100644
--- a/lib/diaspora_federation/federation/sender/hydra_wrapper.rb
+++ b/lib/diaspora_federation/federation/sender/hydra_wrapper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "typhoeus"
 
 module DiasporaFederation
diff --git a/lib/diaspora_federation/http_client.rb b/lib/diaspora_federation/http_client.rb
index 8cf0fa1..df536a0 100644
--- a/lib/diaspora_federation/http_client.rb
+++ b/lib/diaspora_federation/http_client.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "faraday"
 require "faraday_middleware/response/follow_redirects"
 
diff --git a/lib/diaspora_federation/logging.rb b/lib/diaspora_federation/logging.rb
index 4593c28..29fb7b2 100644
--- a/lib/diaspora_federation/logging.rb
+++ b/lib/diaspora_federation/logging.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   # Logging module for the diaspora* federation
   #
diff --git a/lib/diaspora_federation/parsers.rb b/lib/diaspora_federation/parsers.rb
index a08ba5c..783ab8e 100644
--- a/lib/diaspora_federation/parsers.rb
+++ b/lib/diaspora_federation/parsers.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   # This namespace contains parsers which are used to deserialize federation entities
   # objects from supported formats (XML, JSON) to objects of DiasporaFederation::Entity
diff --git a/lib/diaspora_federation/parsers/base_parser.rb b/lib/diaspora_federation/parsers/base_parser.rb
index 50b48b9..a874209 100644
--- a/lib/diaspora_federation/parsers/base_parser.rb
+++ b/lib/diaspora_federation/parsers/base_parser.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Parsers
     # +BaseParser+ is an abstract class which is used for defining parsers for different
@@ -36,6 +38,7 @@ module DiasporaFederation
           text.to_i if text =~ /\A\d+\z/
         when :boolean
           return true if text =~ /\A(true|t|yes|y|1)\z/i
+
           false if text =~ /\A(false|f|no|n|0)\z/i
         else
           text
@@ -44,6 +47,7 @@ module DiasporaFederation
 
       def assert_parsability_of(entity_class)
         return if entity_class == entity_type.entity_name
+
         raise InvalidRootNode, "'#{entity_class}' can't be parsed by #{entity_type.name}"
       end
 
diff --git a/lib/diaspora_federation/parsers/json_parser.rb b/lib/diaspora_federation/parsers/json_parser.rb
index ff7c0aa..1a8642f 100644
--- a/lib/diaspora_federation/parsers/json_parser.rb
+++ b/lib/diaspora_federation/parsers/json_parser.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Parsers
     # This is a parser of JSON serialized object. JSON object format is defined by
@@ -30,12 +32,14 @@ module DiasporaFederation
 
       def parse_element_from_value(type, value)
         return if value.nil?
+
         if %i[integer boolean timestamp].include?(type) && !value.is_a?(String)
           value
         elsif type.instance_of?(Symbol)
           parse_string(type, value)
         elsif type.instance_of?(Array)
           raise DeserializationError, "Expected array for #{type}" unless value.respond_to?(:map)
+
           value.map {|element|
             type.first.from_json(element)
           }
@@ -49,6 +53,7 @@ module DiasporaFederation
           prop if json_hash[prop].nil?
         }.compact.join(", ")
         raise DeserializationError, "Required properties are missing in JSON object: #{missing}" unless missing.empty?
+
         assert_parsability_of(json_hash["entity_type"])
       end
 
diff --git a/lib/diaspora_federation/parsers/relayable_json_parser.rb b/lib/diaspora_federation/parsers/relayable_json_parser.rb
index 192a572..1517737 100644
--- a/lib/diaspora_federation/parsers/relayable_json_parser.rb
+++ b/lib/diaspora_federation/parsers/relayable_json_parser.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Parsers
     # This is a parser of JSON serialized object, that is normally used for parsing data of relayables.
@@ -18,6 +20,7 @@ module DiasporaFederation
       def from_json_sanity_validation(json_hash)
         super
         return unless json_hash["property_order"].nil?
+
         raise DeserializationError, "Required property is missing in JSON object: property_order"
       end
     end
diff --git a/lib/diaspora_federation/parsers/relayable_xml_parser.rb b/lib/diaspora_federation/parsers/relayable_xml_parser.rb
index 272a4ca..4372854 100644
--- a/lib/diaspora_federation/parsers/relayable_xml_parser.rb
+++ b/lib/diaspora_federation/parsers/relayable_xml_parser.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Parsers
     # This is a parser of XML serialized object that is normally used for parsing data of relayables.
diff --git a/lib/diaspora_federation/parsers/xml_parser.rb b/lib/diaspora_federation/parsers/xml_parser.rb
index 2e04418..40acfda 100644
--- a/lib/diaspora_federation/parsers/xml_parser.rb
+++ b/lib/diaspora_federation/parsers/xml_parser.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Parsers
     # This is a parser of XML serialized object.
@@ -77,6 +79,7 @@ module DiasporaFederation
 
       def from_xml_sanity_validation(root_node)
         raise ArgumentError, "only Nokogiri::XML::Element allowed" unless root_node.instance_of?(Nokogiri::XML::Element)
+
         assert_parsability_of(root_node.name)
       end
     end
diff --git a/lib/diaspora_federation/properties_dsl.rb b/lib/diaspora_federation/properties_dsl.rb
index 2b4cef8..b473529 100644
--- a/lib/diaspora_federation/properties_dsl.rb
+++ b/lib/diaspora_federation/properties_dsl.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   # Provides a simple DSL for specifying {Entity} properties during class
   # definition.
@@ -69,6 +71,7 @@ module DiasporaFederation
         if class_prop_aliases.has_key? name
           prop_name = class_prop_aliases[name]
           raise InvalidData, "only use '#{name}' OR '#{prop_name}'" if data.has_key? prop_name
+
           [prop_name, value]
         else
           [name, value]
@@ -86,7 +89,7 @@ module DiasporaFederation
     # @param [String] xml_name name of the property from the received xml
     # @return [Hash] the property data
     def find_property_for_xml_name(xml_name)
-      class_props.keys.find {|name| name.to_s == xml_name || xml_names[name].to_s == xml_name }
+      class_props.keys.find {|name| [name.to_s, xml_names[name].to_s].include?(xml_name) }
     end
 
     private
@@ -100,6 +103,7 @@ module DiasporaFederation
       if type.instance_of?(Symbol)
         if opts.has_key? :xml_name
           raise InvalidName, "invalid xml_name" unless name_valid?(opts[:xml_name])
+
           opts[:xml_name]
         else
           name
diff --git a/lib/diaspora_federation/rails.rb b/lib/diaspora_federation/rails.rb
index dd551a7..cd2577a 100644
--- a/lib/diaspora_federation/rails.rb
+++ b/lib/diaspora_federation/rails.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "diaspora_federation/engine"
 
 require "diaspora_federation"
diff --git a/lib/diaspora_federation/salmon.rb b/lib/diaspora_federation/salmon.rb
index 79c0216..0fc3ef9 100644
--- a/lib/diaspora_federation/salmon.rb
+++ b/lib/diaspora_federation/salmon.rb
@@ -1,9 +1,11 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   # This module contains a diaspora*-specific implementation of parts of the
   # {http://www.salmon-protocol.org/ Salmon Protocol}.
   module Salmon
     # XML namespace url
-    XMLNS = "https://joindiaspora.com/protocol".freeze
+    XMLNS = "https://joindiaspora.com/protocol"
   end
 end
 
diff --git a/lib/diaspora_federation/salmon/aes.rb b/lib/diaspora_federation/salmon/aes.rb
index 9a717c3..cc55e28 100644
--- a/lib/diaspora_federation/salmon/aes.rb
+++ b/lib/diaspora_federation/salmon/aes.rb
@@ -1,9 +1,11 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Salmon
     # Class for AES encryption and decryption
     class AES
       # OpenSSL aes cipher definition
-      CIPHER = "AES-256-CBC".freeze
+      CIPHER = "AES-256-CBC"
 
       # Generates a random AES key and initialization vector
       # @return [Hash] { key: "...", iv: "..." }
diff --git a/lib/diaspora_federation/salmon/encrypted_magic_envelope.rb b/lib/diaspora_federation/salmon/encrypted_magic_envelope.rb
index a883474..83b585d 100644
--- a/lib/diaspora_federation/salmon/encrypted_magic_envelope.rb
+++ b/lib/diaspora_federation/salmon/encrypted_magic_envelope.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Salmon
     # This is a simple crypt-wrapper for {MagicEnvelope}.
diff --git a/lib/diaspora_federation/salmon/encrypted_slap.rb b/lib/diaspora_federation/salmon/encrypted_slap.rb
index 2fa772f..23da393 100644
--- a/lib/diaspora_federation/salmon/encrypted_slap.rb
+++ b/lib/diaspora_federation/salmon/encrypted_slap.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "json"
 
 module DiasporaFederation
@@ -67,10 +69,12 @@ module DiasporaFederation
       # @raise [MissingMagicEnvelope] if the +me:env+ element is missing in the XML
       def self.from_xml(slap_xml, privkey)
         raise ArgumentError unless slap_xml.instance_of?(String) && privkey.instance_of?(OpenSSL::PKey::RSA)
+
         doc = Nokogiri::XML(slap_xml)
 
         header_elem = doc.at_xpath("d:diaspora/d:encrypted_header", Slap::NS)
         raise MissingHeader if header_elem.nil?
+
         header = header_data(header_elem.content, privkey)
         sender = header[:author_id]
         cipher_params = {key: Base64.decode64(header[:aes_key]), iv: Base64.decode64(header[:iv])}
diff --git a/lib/diaspora_federation/salmon/exceptions.rb b/lib/diaspora_federation/salmon/exceptions.rb
index 9dd0f96..07061be 100644
--- a/lib/diaspora_federation/salmon/exceptions.rb
+++ b/lib/diaspora_federation/salmon/exceptions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Salmon
     # Raised, if the element containing the Magic Envelope is missing from the XML
diff --git a/lib/diaspora_federation/salmon/magic_envelope.rb b/lib/diaspora_federation/salmon/magic_envelope.rb
index ac53e95..fcc3f53 100644
--- a/lib/diaspora_federation/salmon/magic_envelope.rb
+++ b/lib/diaspora_federation/salmon/magic_envelope.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Salmon
     # Represents a Magic Envelope for diaspora* federation messages
@@ -24,19 +26,19 @@ module DiasporaFederation
       include Logging
 
       # Encoding used for the payload data
-      ENCODING = "base64url".freeze
+      ENCODING = "base64url"
 
       # Algorithm used for signing the payload data
-      ALGORITHM = "RSA-SHA256".freeze
+      ALGORITHM = "RSA-SHA256"
 
       # Mime type describing the payload data
-      DATA_TYPE = "application/xml".freeze
+      DATA_TYPE = "application/xml"
 
       # Digest instance used for signing
       DIGEST = OpenSSL::Digest::SHA256.new
 
       # XML namespace url
-      XMLNS = "http://salmon-protocol.org/ns/magic-env".freeze
+      XMLNS = "http://salmon-protocol.org/ns/magic-env"
 
       # The payload entity of the magic envelope
       # @return [Entity] payload entity
@@ -153,6 +155,7 @@ module DiasporaFederation
       # @raise [InvalidEnvelope] if the envelope XML structure is malformed
       private_class_method def self.validate_envelope(env)
         raise InvalidEnvelope unless env.instance_of?(Nokogiri::XML::Element) && env.name == "env"
+
         validate_element(env, "me:data")
         validate_element(env, "me:sig")
       end
@@ -188,6 +191,7 @@ module DiasporaFederation
       private_class_method def self.sender(env)
         key_id = env.at_xpath("me:sig")["key_id"]
         raise InvalidEnvelope, "no key_id" unless key_id # TODO: move to `envelope_valid?`
+
         Base64.urlsafe_decode64(key_id)
       end
 
diff --git a/lib/diaspora_federation/salmon/slap.rb b/lib/diaspora_federation/salmon/slap.rb
index f0daa92..242337d 100644
--- a/lib/diaspora_federation/salmon/slap.rb
+++ b/lib/diaspora_federation/salmon/slap.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Salmon
     # +Slap+ provides class methods to create unencrypted Slap XML from payload
@@ -33,10 +35,12 @@ module DiasporaFederation
       # @raise [MissingMagicEnvelope] if the +me:env+ element is missing from the XML
       def self.from_xml(slap_xml)
         raise ArgumentError unless slap_xml.instance_of?(String)
+
         doc = Nokogiri::XML(slap_xml)
 
         author_elem = doc.at_xpath("d:diaspora/d:header/d:author_id", Slap::NS)
         raise MissingAuthor if author_elem.nil? || author_elem.content.empty?
+
         sender = author_elem.content
 
         MagicEnvelope.unenvelop(magic_env_from_doc(doc), sender)
diff --git a/lib/diaspora_federation/salmon/xml_payload.rb b/lib/diaspora_federation/salmon/xml_payload.rb
index 90d8557..32ea453 100644
--- a/lib/diaspora_federation/salmon/xml_payload.rb
+++ b/lib/diaspora_federation/salmon/xml_payload.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Salmon
     # +XmlPayload+ provides methods to wrap a XML-serialized {Entity} inside a
diff --git a/lib/diaspora_federation/schemas.rb b/lib/diaspora_federation/schemas.rb
index 5b7120a..d04de47 100644
--- a/lib/diaspora_federation/schemas.rb
+++ b/lib/diaspora_federation/schemas.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "pathname"
 require "json"
 
@@ -5,7 +7,7 @@ module DiasporaFederation
   # A helper class to access the JSON schema.
   module Schemas
     # federation_entities schema uri
-    FEDERATION_ENTITIES_URI = "https://diaspora.github.io/diaspora_federation/schemas/federation_entities.json".freeze
+    FEDERATION_ENTITIES_URI = "https://diaspora.github.io/diaspora_federation/schemas/federation_entities.json"
 
     # Parsed federation_entities schema
     def self.federation_entities
diff --git a/lib/diaspora_federation/test.rb b/lib/diaspora_federation/test.rb
index db81377..60e136f 100644
--- a/lib/diaspora_federation/test.rb
+++ b/lib/diaspora_federation/test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "fabrication"
 
 require "diaspora_federation"
diff --git a/lib/diaspora_federation/test/entity_generator.rb b/lib/diaspora_federation/test/entity_generator.rb
index 1f9c7e6..9e610c0 100644
--- a/lib/diaspora_federation/test/entity_generator.rb
+++ b/lib/diaspora_federation/test/entity_generator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Test
     # Generator to instantiate entities
diff --git a/lib/diaspora_federation/test/factories.rb b/lib/diaspora_federation/test/factories.rb
index 38e8d99..92dd1c0 100644
--- a/lib/diaspora_federation/test/factories.rb
+++ b/lib/diaspora_federation/test/factories.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "uuid"
 require "securerandom"
 require "diaspora_federation/test"
diff --git a/lib/diaspora_federation/validators.rb b/lib/diaspora_federation/validators.rb
index 986daef..4ab6a70 100644
--- a/lib/diaspora_federation/validators.rb
+++ b/lib/diaspora_federation/validators.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "validation"
 require "validation/rule/regular_expression"
 require "validation/rule/length"
diff --git a/lib/diaspora_federation/validators/account_deletion_validator.rb b/lib/diaspora_federation/validators/account_deletion_validator.rb
index 60a32cf..f297e37 100644
--- a/lib/diaspora_federation/validators/account_deletion_validator.rb
+++ b/lib/diaspora_federation/validators/account_deletion_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Validators
     # This validates a {Entities::AccountDeletion}.
diff --git a/lib/diaspora_federation/validators/account_migration_validator.rb b/lib/diaspora_federation/validators/account_migration_validator.rb
index 36c38be..206a2ff 100644
--- a/lib/diaspora_federation/validators/account_migration_validator.rb
+++ b/lib/diaspora_federation/validators/account_migration_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Validators
     # This validates a {Entities::AccountMigration}.
diff --git a/lib/diaspora_federation/validators/comment_validator.rb b/lib/diaspora_federation/validators/comment_validator.rb
index 4669f50..3f4ac65 100644
--- a/lib/diaspora_federation/validators/comment_validator.rb
+++ b/lib/diaspora_federation/validators/comment_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Validators
     # This validates a {Entities::Comment}.
diff --git a/lib/diaspora_federation/validators/contact_validator.rb b/lib/diaspora_federation/validators/contact_validator.rb
index cf313cc..d8f4f2c 100644
--- a/lib/diaspora_federation/validators/contact_validator.rb
+++ b/lib/diaspora_federation/validators/contact_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Validators
     # This validates a {Entities::Contact}.
diff --git a/lib/diaspora_federation/validators/conversation_validator.rb b/lib/diaspora_federation/validators/conversation_validator.rb
index 1e66994..da984c6 100644
--- a/lib/diaspora_federation/validators/conversation_validator.rb
+++ b/lib/diaspora_federation/validators/conversation_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Validators
     # This validates a {Entities::Conversation}.
diff --git a/lib/diaspora_federation/validators/embed_validator.rb b/lib/diaspora_federation/validators/embed_validator.rb
index de766cc..6486035 100644
--- a/lib/diaspora_federation/validators/embed_validator.rb
+++ b/lib/diaspora_federation/validators/embed_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Validators
     # This validates a {Entities::Embed}.
diff --git a/lib/diaspora_federation/validators/event_participation_validator.rb b/lib/diaspora_federation/validators/event_participation_validator.rb
index 8e1209f..cfa6f61 100644
--- a/lib/diaspora_federation/validators/event_participation_validator.rb
+++ b/lib/diaspora_federation/validators/event_participation_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Validators
     # This validates a {Entities::EventParticipation}.
diff --git a/lib/diaspora_federation/validators/event_validator.rb b/lib/diaspora_federation/validators/event_validator.rb
index a6c0aa6..ce37dbe 100644
--- a/lib/diaspora_federation/validators/event_validator.rb
+++ b/lib/diaspora_federation/validators/event_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Validators
     # This validates a {Entities::Event}.
diff --git a/lib/diaspora_federation/validators/h_card_validator.rb b/lib/diaspora_federation/validators/h_card_validator.rb
index 236d88e..6612e1b 100644
--- a/lib/diaspora_federation/validators/h_card_validator.rb
+++ b/lib/diaspora_federation/validators/h_card_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Validators
     # This validates a {Discovery::HCard}.
diff --git a/lib/diaspora_federation/validators/like_validator.rb b/lib/diaspora_federation/validators/like_validator.rb
index 60bb64c..97490b3 100644
--- a/lib/diaspora_federation/validators/like_validator.rb
+++ b/lib/diaspora_federation/validators/like_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Validators
     # This validates a {Entities::Like}.
diff --git a/lib/diaspora_federation/validators/location_validator.rb b/lib/diaspora_federation/validators/location_validator.rb
index cd6e952..656f82e 100644
--- a/lib/diaspora_federation/validators/location_validator.rb
+++ b/lib/diaspora_federation/validators/location_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Validators
     # This validates a {Entities::Location}.
diff --git a/lib/diaspora_federation/validators/message_validator.rb b/lib/diaspora_federation/validators/message_validator.rb
index 6ded966..9064a06 100644
--- a/lib/diaspora_federation/validators/message_validator.rb
+++ b/lib/diaspora_federation/validators/message_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Validators
     # This validates a {Entities::Message}.
diff --git a/lib/diaspora_federation/validators/optional_aware_validator.rb b/lib/diaspora_federation/validators/optional_aware_validator.rb
index 1c0b467..d7eceaf 100644
--- a/lib/diaspora_federation/validators/optional_aware_validator.rb
+++ b/lib/diaspora_federation/validators/optional_aware_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Validators
     # Abstract validator which only validates optional fields when they are not nil.
@@ -14,6 +16,7 @@ module DiasporaFederation
 
       def optional_props
         return [] unless @obj.class.respond_to?(:optional_props)
+
         @obj.class.optional_props
       end
     end
diff --git a/lib/diaspora_federation/validators/participation_validator.rb b/lib/diaspora_federation/validators/participation_validator.rb
index c3c4917..315887b 100644
--- a/lib/diaspora_federation/validators/participation_validator.rb
+++ b/lib/diaspora_federation/validators/participation_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Validators
     # This validates a {Entities::Participation}.
diff --git a/lib/diaspora_federation/validators/person_validator.rb b/lib/diaspora_federation/validators/person_validator.rb
index ddfad99..147da56 100644
--- a/lib/diaspora_federation/validators/person_validator.rb
+++ b/lib/diaspora_federation/validators/person_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Validators
     # This validates a {Entities::Person}.
diff --git a/lib/diaspora_federation/validators/photo_validator.rb b/lib/diaspora_federation/validators/photo_validator.rb
index 7c18107..02af975 100644
--- a/lib/diaspora_federation/validators/photo_validator.rb
+++ b/lib/diaspora_federation/validators/photo_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Validators
     # This validates a {Entities::Photo}.
diff --git a/lib/diaspora_federation/validators/poll_answer_validator.rb b/lib/diaspora_federation/validators/poll_answer_validator.rb
index 4c55f05..b22668b 100644
--- a/lib/diaspora_federation/validators/poll_answer_validator.rb
+++ b/lib/diaspora_federation/validators/poll_answer_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Validators
     # This validates a {Entities::PollAnswer}.
diff --git a/lib/diaspora_federation/validators/poll_participation_validator.rb b/lib/diaspora_federation/validators/poll_participation_validator.rb
index 65cb7db..8410c22 100644
--- a/lib/diaspora_federation/validators/poll_participation_validator.rb
+++ b/lib/diaspora_federation/validators/poll_participation_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Validators
     # This validates a {Entities::PollParticipation}.
diff --git a/lib/diaspora_federation/validators/poll_validator.rb b/lib/diaspora_federation/validators/poll_validator.rb
index 103b85f..1a8a49e 100644
--- a/lib/diaspora_federation/validators/poll_validator.rb
+++ b/lib/diaspora_federation/validators/poll_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Validators
     # This validates a {Entities::Poll}.
diff --git a/lib/diaspora_federation/validators/profile_validator.rb b/lib/diaspora_federation/validators/profile_validator.rb
index 38ef3e3..cea39be 100644
--- a/lib/diaspora_federation/validators/profile_validator.rb
+++ b/lib/diaspora_federation/validators/profile_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Validators
     # This validates a {Entities::Profile}.
diff --git a/lib/diaspora_federation/validators/related_entity_validator.rb b/lib/diaspora_federation/validators/related_entity_validator.rb
index 17c2726..0c6e99f 100644
--- a/lib/diaspora_federation/validators/related_entity_validator.rb
+++ b/lib/diaspora_federation/validators/related_entity_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Validators
     # This validates a {Entities::RelatedEntity}.
diff --git a/lib/diaspora_federation/validators/relayable_validator.rb b/lib/diaspora_federation/validators/relayable_validator.rb
index 618f3ce..11f155f 100644
--- a/lib/diaspora_federation/validators/relayable_validator.rb
+++ b/lib/diaspora_federation/validators/relayable_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Validators
     # This is included to validatros which validate entities which include {Entities::Relayable}.
diff --git a/lib/diaspora_federation/validators/reshare_validator.rb b/lib/diaspora_federation/validators/reshare_validator.rb
index 343e36b..46de5e6 100644
--- a/lib/diaspora_federation/validators/reshare_validator.rb
+++ b/lib/diaspora_federation/validators/reshare_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Validators
     # This validates a {Entities::Reshare}.
diff --git a/lib/diaspora_federation/validators/retraction_validator.rb b/lib/diaspora_federation/validators/retraction_validator.rb
index 922b44f..6400ae0 100644
--- a/lib/diaspora_federation/validators/retraction_validator.rb
+++ b/lib/diaspora_federation/validators/retraction_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Validators
     # This validates a {Entities::Retraction}.
diff --git a/lib/diaspora_federation/validators/rules/birthday.rb b/lib/diaspora_federation/validators/rules/birthday.rb
index c780f34..21c28a0 100644
--- a/lib/diaspora_federation/validators/rules/birthday.rb
+++ b/lib/diaspora_federation/validators/rules/birthday.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "date"
 
 module Validation
@@ -20,7 +22,7 @@ module Validation
         return true if value.nil? || (value.is_a?(String) && value.empty?)
         return true if value.is_a? Date
 
-        if value =~ /[0-9]{4}\-[0-9]{2}\-[0-9]{2}/
+        if value.is_a?(String) && value.match?(/[0-9]{4}\-[0-9]{2}\-[0-9]{2}/)
           date_field = value.split("-").map(&:to_i)
           return Date.valid_civil?(date_field[0], date_field[1], date_field[2])
         end
diff --git a/lib/diaspora_federation/validators/rules/boolean.rb b/lib/diaspora_federation/validators/rules/boolean.rb
index 6c0418d..01f0e30 100644
--- a/lib/diaspora_federation/validators/rules/boolean.rb
+++ b/lib/diaspora_federation/validators/rules/boolean.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Validation
   module Rule
     # Boolean validation rule
diff --git a/lib/diaspora_federation/validators/rules/diaspora_id.rb b/lib/diaspora_federation/validators/rules/diaspora_id.rb
index 42bcc0b..b2b696a 100644
--- a/lib/diaspora_federation/validators/rules/diaspora_id.rb
+++ b/lib/diaspora_federation/validators/rules/diaspora_id.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Validation
   module Rule
     # diaspora* ID validation rule
@@ -22,7 +24,7 @@ module Validation
       end
 
       # The Regex for validating a full diaspora* ID
-      DIASPORA_ID = /\A#{DIASPORA_ID_REGEX}\z/u
+      DIASPORA_ID = /\A#{DIASPORA_ID_REGEX}\z/u.freeze
 
       # The error key for this rule
       # @return [Symbol] error key
diff --git a/lib/diaspora_federation/validators/rules/diaspora_id_list.rb b/lib/diaspora_federation/validators/rules/diaspora_id_list.rb
index 85e1937..322eb98 100644
--- a/lib/diaspora_federation/validators/rules/diaspora_id_list.rb
+++ b/lib/diaspora_federation/validators/rules/diaspora_id_list.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Validation
   module Rule
     # Rule for validating the number of diaspora* IDs in a string.
@@ -31,6 +33,7 @@ module Validation
         ids = value.split(";")
         return false if params.include?(:maximum) && ids.count > params[:maximum]
         return false if params.include?(:minimum) && ids.count < params[:minimum]
+
         ids.each do |id|
           return false if DiasporaId::DIASPORA_ID.match(id).nil?
         end
diff --git a/lib/diaspora_federation/validators/rules/guid.rb b/lib/diaspora_federation/validators/rules/guid.rb
index 3e30874..23f1748 100644
--- a/lib/diaspora_federation/validators/rules/guid.rb
+++ b/lib/diaspora_federation/validators/rules/guid.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Validation
   module Rule
     # GUID validation rule
@@ -9,7 +11,7 @@ module Validation
     # Special chars aren't allowed at the end.
     class Guid
       # Allowed chars to validate a GUID with a regex
-      VALID_CHARS = "[0-9A-Za-z\\-_@.:]{15,254}[0-9A-Za-z]".freeze
+      VALID_CHARS = "[0-9A-Za-z\\-_@.:]{15,254}[0-9A-Za-z]"
 
       # The error key for this rule
       # @return [Symbol] error key
diff --git a/lib/diaspora_federation/validators/rules/not_nil.rb b/lib/diaspora_federation/validators/rules/not_nil.rb
index 3fb6950..ce3b2c0 100644
--- a/lib/diaspora_federation/validators/rules/not_nil.rb
+++ b/lib/diaspora_federation/validators/rules/not_nil.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Validation
   module Rule
     # Validates that a property is not +nil+
diff --git a/lib/diaspora_federation/validators/rules/public_key.rb b/lib/diaspora_federation/validators/rules/public_key.rb
index 7b94802..77a2227 100644
--- a/lib/diaspora_federation/validators/rules/public_key.rb
+++ b/lib/diaspora_federation/validators/rules/public_key.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Validation
   module Rule
     # Public key validation rule
diff --git a/lib/diaspora_federation/validators/rules/tag_count.rb b/lib/diaspora_federation/validators/rules/tag_count.rb
index 4033605..ccf249a 100644
--- a/lib/diaspora_federation/validators/rules/tag_count.rb
+++ b/lib/diaspora_federation/validators/rules/tag_count.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module Validation
   module Rule
     # Rule for validating the number of tags in a string.
diff --git a/lib/diaspora_federation/validators/status_message_validator.rb b/lib/diaspora_federation/validators/status_message_validator.rb
index 62eee98..6b70b55 100644
--- a/lib/diaspora_federation/validators/status_message_validator.rb
+++ b/lib/diaspora_federation/validators/status_message_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Validators
     # This validates a {Entities::StatusMessage}.
diff --git a/lib/diaspora_federation/validators/web_finger_validator.rb b/lib/diaspora_federation/validators/web_finger_validator.rb
index 596f14c..8769750 100644
--- a/lib/diaspora_federation/validators/web_finger_validator.rb
+++ b/lib/diaspora_federation/validators/web_finger_validator.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Validators
     # This validates a {Discovery::WebFinger}.
diff --git a/lib/diaspora_federation/version.rb b/lib/diaspora_federation/version.rb
index 1255d74..7f64d6c 100644
--- a/lib/diaspora_federation/version.rb
+++ b/lib/diaspora_federation/version.rb
@@ -1,4 +1,6 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   # the gem version
-  VERSION = "0.2.6".freeze
+  VERSION = "0.2.6"
 end
diff --git a/lib/tasks/build.rake b/lib/tasks/build.rake
index ef74168..945f47b 100644
--- a/lib/tasks/build.rake
+++ b/lib/tasks/build.rake
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 desc "Build gem into the pkg directory"
 task build: :test do
   FileUtils.rm_rf("pkg")
diff --git a/lib/tasks/gemfiles.rake b/lib/tasks/gemfiles.rake
index 124f386..3500bdd 100644
--- a/lib/tasks/gemfiles.rake
+++ b/lib/tasks/gemfiles.rake
@@ -1,5 +1,7 @@
+# frozen_string_literal: true
+
 namespace :gemfiles do
-  desc "Generates rails4.Gemfile and no-rails.Gemfile"
+  desc "Generates no-rails.Gemfile"
   task :generate do
     FileUtils.mkdir_p("test/gemfiles")
     FileUtils.rm(Dir["test/gemfiles/*.Gemfile.lock"])
@@ -8,12 +10,6 @@ namespace :gemfiles do
     original_gemfile.sub!(/(gemspec name:.*)/) { "#{Regexp.last_match[1]}, path: \"../../\"" }
     original_gemfile.sub!(/(gemspec\(name:.*)\)/) { "#{Regexp.last_match[1]}, path: \"../../\")" }
     original_gemfile.sub!(/^group :development do$.*?^end$\n\n/m, "")
-    original_gemfile << "\n gem \"fabrication\", \"< 2.17.0\"\n" # new versions are not compatible with ruby 2.1
-
-    rails4_version = "4.2.8"
-    rails4_gemfile = "#{original_gemfile}\ngem \"actionpack\", \"#{rails4_version}\"\n"
-    rails4_path = "test/gemfiles/rails4.Gemfile"
-    File.write(rails4_path, rails4_gemfile)
 
     no_rails_gemfile = original_gemfile.dup
     no_rails_gemfile.sub!(/(gemspec\(name:.*)/) { "#{Regexp.last_match[1]} unless plugin == \"rails\"" }
@@ -22,7 +18,6 @@ namespace :gemfiles do
     File.write(no_rails_path, no_rails_gemfile)
 
     Bundler.with_clean_env do
-      system("BUNDLE_GEMFILE=#{rails4_path} bundle install")
       system("BUNDLE_GEMFILE=#{no_rails_path} bundle install")
     end
   end
diff --git a/spec/controllers/diaspora_federation/application_controller_spec.rb b/spec/controllers/diaspora_federation/application_controller_spec.rb
index 79084c4..70bf828 100644
--- a/spec/controllers/diaspora_federation/application_controller_spec.rb
+++ b/spec/controllers/diaspora_federation/application_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe ApplicationController, type: :controller do
     controller do
diff --git a/spec/controllers/diaspora_federation/fetch_controller_spec.rb b/spec/controllers/diaspora_federation/fetch_controller_spec.rb
index 235783b..ec80207 100644
--- a/spec/controllers/diaspora_federation/fetch_controller_spec.rb
+++ b/spec/controllers/diaspora_federation/fetch_controller_spec.rb
@@ -1,5 +1,7 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
-  describe FetchController, type: :controller, rails: 5 do
+  describe FetchController, type: :controller do
     routes { DiasporaFederation::Engine.routes }
 
     let(:guid) { "12345678901234567890" }
diff --git a/spec/controllers/diaspora_federation/h_card_controller_spec.rb b/spec/controllers/diaspora_federation/h_card_controller_spec.rb
index 9ebbfd9..1cf805b 100644
--- a/spec/controllers/diaspora_federation/h_card_controller_spec.rb
+++ b/spec/controllers/diaspora_federation/h_card_controller_spec.rb
@@ -1,5 +1,7 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
-  describe HCardController, type: :controller, rails: 5 do
+  describe HCardController, type: :controller do
     routes { DiasporaFederation::Engine.routes }
 
     describe "GET #hcard" do
diff --git a/spec/controllers/diaspora_federation/rails4_spec.rb b/spec/controllers/diaspora_federation/rails4_spec.rb
deleted file mode 100644
index 7225c9a..0000000
--- a/spec/controllers/diaspora_federation/rails4_spec.rb
+++ /dev/null
@@ -1,81 +0,0 @@
-# only some basic controller tests for rails 4
-module DiasporaFederation
-  describe WebfingerController, type: :controller, rails: 4 do
-    routes { DiasporaFederation::Engine.routes }
-
-    it "contains the webfinger result" do
-      webfinger_xrd = DiasporaFederation::Discovery::WebFinger.new(
-        acct_uri:      "acct:#{alice.diaspora_id}",
-        alias_url:     alice.alias_url,
-        hcard_url:     alice.hcard_url,
-        seed_url:      alice.url,
-        profile_url:   alice.profile_url,
-        atom_url:      alice.atom_url,
-        salmon_url:    alice.salmon_url,
-        subscribe_url: alice.subscribe_url,
-        guid:          alice.guid,
-        public_key:    alice.serialized_public_key
-      ).to_xml
-
-      get :webfinger, format: :xml, resource: alice.diaspora_id
-      expect(response).to be_success
-      expect(response.body).to eq(webfinger_xrd)
-    end
-
-    it "404s when the person does not exist" do
-      get :webfinger, format: :xml, resource: "me@mydiaspora.pod.com"
-      expect(response).to be_not_found
-    end
-  end
-
-  describe HCardController, type: :controller, rails: 4 do
-    routes { DiasporaFederation::Engine.routes }
-
-    it "contains the hcard result" do
-      hcard_html = DiasporaFederation::Discovery::HCard.new(
-        guid:             alice.guid,
-        nickname:         alice.nickname,
-        full_name:        alice.full_name,
-        url:              alice.url,
-        photo_large_url:  alice.photo_default_url,
-        photo_medium_url: alice.photo_default_url,
-        photo_small_url:  alice.photo_default_url,
-        public_key:       alice.serialized_public_key,
-        searchable:       alice.searchable,
-        first_name:       alice.first_name,
-        last_name:        alice.last_name
-      ).to_html
-
-      get :hcard, guid: alice.guid
-      expect(response).to be_success
-      expect(response.body).to eq(hcard_html)
-    end
-
-    it "404s when the person does not exist" do
-      get :hcard, guid: "unknown_guid"
-      expect(response).to be_not_found
-    end
-  end
-
-  describe ReceiveController, type: :controller, rails: 4 do
-    routes { DiasporaFederation::Engine.routes }
-
-    describe "POST #public" do
-      it "returns a 202 if queued correctly" do
-        expect_callback(:queue_public_receive, "<diaspora/>", true)
-
-        post :public, xml: "<diaspora/>"
-        expect(response.code).to eq("202")
-      end
-    end
-
-    describe "POST #private" do
-      it "returns a 202 if the callback returned true" do
-        expect_callback(:queue_private_receive, "any-guid", "<diaspora/>", true).and_return(true)
-
-        post :private, guid: "any-guid", xml: "<diaspora/>"
-        expect(response.code).to eq("202")
-      end
-    end
-  end
-end
diff --git a/spec/controllers/diaspora_federation/receive_controller_spec.rb b/spec/controllers/diaspora_federation/receive_controller_spec.rb
index b480f48..0d5b684 100644
--- a/spec/controllers/diaspora_federation/receive_controller_spec.rb
+++ b/spec/controllers/diaspora_federation/receive_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe ReceiveController, type: :controller do
     routes { DiasporaFederation::Engine.routes }
@@ -15,21 +17,21 @@ module DiasporaFederation
           expect(response.code).to eq("422")
         end
 
-        it "returns a 202 if queued correctly", rails: 5 do
+        it "returns a 202 if queued correctly" do
           expect_callback(:queue_public_receive, "<diaspora/>", true)
 
           post :public, params: {xml: "<diaspora/>"}
           expect(response.code).to eq("202")
         end
 
-        it "unescapes the xml before sending it to the callback", rails: 5 do
+        it "unescapes the xml before sending it to the callback" do
           expect_callback(:queue_public_receive, "<diaspora/>", true)
 
           post :public, params: {xml: CGI.escape("<diaspora/>")}
         end
       end
 
-      context "magic envelope", rails: 5 do
+      context "magic envelope" do
         before do
           Mime::Type.register("application/magic-envelope+xml", :magic_envelope)
           @request.env["CONTENT_TYPE"] = "application/magic-envelope+xml"
@@ -38,13 +40,13 @@ module DiasporaFederation
         it "returns a 202 if queued correctly" do
           expect_callback(:queue_public_receive, "<me:env/>", false)
 
-          post :public, body: "<me:env/>"
+          post :public, body: +"<me:env/>"
           expect(response.code).to eq("202")
         end
       end
     end
 
-    describe "POST #private", rails: 5 do
+    describe "POST #private" do
       context "legacy salmon slap" do
         it "return a 404 if not queued successfully (unknown user guid)" do
           expect_callback(:queue_private_receive, "any-guid", "<diaspora/>", true).and_return(false)
@@ -89,7 +91,7 @@ module DiasporaFederation
           ).and_return(false)
 
           post :private,
-               body:   "{\"aes_key\": \"key\", \"encrypted_magic_envelope\": \"env\"}",
+               body:   +"{\"aes_key\": \"key\", \"encrypted_magic_envelope\": \"env\"}",
                params: {guid: "any-guid"}
           expect(response.code).to eq("404")
         end
@@ -100,7 +102,7 @@ module DiasporaFederation
           ).and_return(true)
 
           post :private,
-               body:   "{\"aes_key\": \"key\", \"encrypted_magic_envelope\": \"env\"}",
+               body:   +"{\"aes_key\": \"key\", \"encrypted_magic_envelope\": \"env\"}",
                params: {guid: "any-guid"}
           expect(response.code).to eq("202")
         end
diff --git a/spec/controllers/diaspora_federation/webfinger_controller_spec.rb b/spec/controllers/diaspora_federation/webfinger_controller_spec.rb
index b1796c6..c1a4fa1 100644
--- a/spec/controllers/diaspora_federation/webfinger_controller_spec.rb
+++ b/spec/controllers/diaspora_federation/webfinger_controller_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe WebfingerController, type: :controller do
     routes { DiasporaFederation::Engine.routes }
@@ -35,7 +37,7 @@ module DiasporaFederation
       end
     end
 
-    describe "GET #webfinger", rails: 5 do
+    describe "GET #webfinger" do
       it "uses the JRD format as default" do
         get :webfinger, params: {resource: alice.diaspora_id}
         expect(response).to be_successful
diff --git a/spec/entities.rb b/spec/entities.rb
index c370a91..429ea8a 100644
--- a/spec/entities.rb
+++ b/spec/entities.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   module Entities
     class TestEntity < DiasporaFederation::Entity
@@ -70,7 +72,7 @@ module DiasporaFederation
     end
 
     class SomeRelayable < DiasporaFederation::Entity
-      PARENT_TYPE = "Parent".freeze
+      PARENT_TYPE = "Parent"
 
       include Entities::Relayable
 
@@ -78,7 +80,7 @@ module DiasporaFederation
     end
 
     class TestRelayableWithBoolean < DiasporaFederation::Entity
-      PARENT_TYPE = "Parent".freeze
+      PARENT_TYPE = "Parent"
 
       include Entities::Relayable
 
diff --git a/spec/factories.rb b/spec/factories.rb
index 8bd3e67..bbba632 100644
--- a/spec/factories.rb
+++ b/spec/factories.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "diaspora_federation/test/factories"
 
 Fabricator(:person) do
diff --git a/spec/integration/comment_integration_spec.rb b/spec/integration/comment_integration_spec.rb
index 838f7b4..f713699 100644
--- a/spec/integration/comment_integration_spec.rb
+++ b/spec/integration/comment_integration_spec.rb
@@ -1,22 +1,24 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::Relayable do
-    let(:author_serialized_key) { <<-KEY }
------BEGIN RSA PRIVATE KEY-----
-MIICXgIBAAKBgQCxTbMp+M5sCUDVi9k1wMxedSwyLQcjBKQa0Qs6Qpnflz0k90hh
-btau0cy9jTK6S3CK2GhERXD6EecDlhZCbnSI9Bwmco5j6NbGPN5ai9tWgiBZzaEr
-yOVMQ4qCh1fKOMPX/LCvPzH+K7f8Q92zCuSvKSofg6zpg1zxGahpmxwqFQIDAQAB
-AoGBAKEXD2la/XF7FsTuwvLrsMNBgl40Ov+9/7u9oo3UZSmYp50mb0TXB4beZz7x
-Qt2wHRiJdnJRBUyvZ00C2EaTRJyFJA8p5J2qzHSjGpbPGyRCZUB6r6y+9vbM4ouj
-m5Vo47TQ7ob2D835BHJGR8dWM1zeAwWc6uLhNIu+/5lHQ90BAkEA6aVQFSXNYjmO
-fo6Oro+2nDaoa4jJ9qO1S23P2HF9N2f7CHDB4WKTdYnZpXs7ZPbnMEz62LeSC1MZ
-QOKGYkMuDQJBAMJEZWvfWtp+Zwm+IF1xGbNPzGrvHGJarE/QGUGYs7BR7tHFlepR
-aV3g56eGWfCWk8oWZRbjC2eQ2we96CU4cikCQQCqp3BCwgWthNSrY3yby6RZnSKO
-yK6bUx+MJHz3Xo1S9sPIenNiKBoEc9dgow3SxPQ/tzpRKGOnmd6MIeh9xQvRAkAV
-6WEHKco1msxEbQ15fKhJcVa9OPsanN+SoQY4P+EEojktr/uY0lXwIM4AN0ctu84v
-nRcJ3dILfGs4FFN630MBAkEA3zMOyNTeNdHrVhZc5b0qw2T6FUJGieDpOWLsff4w
-84yW10oS2CCmqEhbfh4Wu22amglytrATwD9hDzsTNAt8Mg==
------END RSA PRIVATE KEY-----
-KEY
+    let(:author_serialized_key) { <<~KEY }
+      -----BEGIN RSA PRIVATE KEY-----
+      MIICXgIBAAKBgQCxTbMp+M5sCUDVi9k1wMxedSwyLQcjBKQa0Qs6Qpnflz0k90hh
+      btau0cy9jTK6S3CK2GhERXD6EecDlhZCbnSI9Bwmco5j6NbGPN5ai9tWgiBZzaEr
+      yOVMQ4qCh1fKOMPX/LCvPzH+K7f8Q92zCuSvKSofg6zpg1zxGahpmxwqFQIDAQAB
+      AoGBAKEXD2la/XF7FsTuwvLrsMNBgl40Ov+9/7u9oo3UZSmYp50mb0TXB4beZz7x
+      Qt2wHRiJdnJRBUyvZ00C2EaTRJyFJA8p5J2qzHSjGpbPGyRCZUB6r6y+9vbM4ouj
+      m5Vo47TQ7ob2D835BHJGR8dWM1zeAwWc6uLhNIu+/5lHQ90BAkEA6aVQFSXNYjmO
+      fo6Oro+2nDaoa4jJ9qO1S23P2HF9N2f7CHDB4WKTdYnZpXs7ZPbnMEz62LeSC1MZ
+      QOKGYkMuDQJBAMJEZWvfWtp+Zwm+IF1xGbNPzGrvHGJarE/QGUGYs7BR7tHFlepR
+      aV3g56eGWfCWk8oWZRbjC2eQ2we96CU4cikCQQCqp3BCwgWthNSrY3yby6RZnSKO
+      yK6bUx+MJHz3Xo1S9sPIenNiKBoEc9dgow3SxPQ/tzpRKGOnmd6MIeh9xQvRAkAV
+      6WEHKco1msxEbQ15fKhJcVa9OPsanN+SoQY4P+EEojktr/uY0lXwIM4AN0ctu84v
+      nRcJ3dILfGs4FFN630MBAkEA3zMOyNTeNdHrVhZc5b0qw2T6FUJGieDpOWLsff4w
+      84yW10oS2CCmqEhbfh4Wu22amglytrATwD9hDzsTNAt8Mg==
+      -----END RSA PRIVATE KEY-----
+    KEY
     let(:author_key) { OpenSSL::PKey::RSA.new(author_serialized_key) }
     # -----BEGIN PUBLIC KEY-----
     # MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCxTbMp+M5sCUDVi9k1wMxedSwy
@@ -25,23 +27,23 @@ KEY
     # g6zpg1zxGahpmxwqFQIDAQAB
     # -----END PUBLIC KEY-----
 
-    let(:parent_serialized_key) { <<-KEY }
------BEGIN RSA PRIVATE KEY-----
-MIICXgIBAAKBgQDrOvW1UArKoUOg54XWXcTD3jU0zKG3Pm9IeaEzfQtApogQ3+M/
-F9nz0i3q8UhTDEPBQ3hMbqJ/4qfY+wFulxMR58DbqxFx9QcNZISUd0CPx/fJOYMx
-R7bygTbiCet4FAiyMjxOX3Oei/DedUNps1RAP1bu+80iibze/Kk9BgMm0QIDAQAB
-AoGAMHvikRCCaOl8SvnteBWzrLtsNAnJez9/KG0JcNdhLl4kxXWgHS0JW1wC4t4A
-jj2E6ZzCet6C1+Ebv3lc/jJdV3pCK3wgX0YAt/oBW5kcuvpLHLSWusWHnHkYU+qO
-4SdC3bRhdLV9o3u/oCWzmdeKTdqIyNd2yAbb3W1TsD4EsQECQQD6w+vWVKhWbVOj
-Ky3ZkLCxPcWNUt+7OIzDA1OLKhdhe44hIoRMfDT6iLK3sJTSjgOv0OFTfsdOqh5y
-ZqYp/CTpAkEA8CQFKkAYt4qG1lKMPsU/Tme0/Z24VozDRnyw7r663f0De+25kXGY
-PSBiOHYcAE6poYQEtR/leLTSaG3YZm7hqQJBAOLAWLg1Uwbb0v4/pDUQlgWfQsy4
-/KAx0W7hyiCTzhKTBAFIUfNLeSh2hYx+ewQt8H2B1s6GXDjwsZlm4qgiXUkCQQC9
-B12ZeIL8V2r0Yl5LOvEuQqxRx0lHt94vKhAMns5x16xabTLZrlVsKIWodDBufX1B
-yq359XWooo3N7kmduEKhAkEAppzKLuVtX1XPL4VZBex/M2ewngjkSg964BvxIBwv
-bFzeSqlMpnbEoOJ9hhx6CsP6Y7V19DRRXi0XgwcAjHLz8g==
------END RSA PRIVATE KEY-----
-KEY
+    let(:parent_serialized_key) { <<~KEY }
+      -----BEGIN RSA PRIVATE KEY-----
+      MIICXgIBAAKBgQDrOvW1UArKoUOg54XWXcTD3jU0zKG3Pm9IeaEzfQtApogQ3+M/
+      F9nz0i3q8UhTDEPBQ3hMbqJ/4qfY+wFulxMR58DbqxFx9QcNZISUd0CPx/fJOYMx
+      R7bygTbiCet4FAiyMjxOX3Oei/DedUNps1RAP1bu+80iibze/Kk9BgMm0QIDAQAB
+      AoGAMHvikRCCaOl8SvnteBWzrLtsNAnJez9/KG0JcNdhLl4kxXWgHS0JW1wC4t4A
+      jj2E6ZzCet6C1+Ebv3lc/jJdV3pCK3wgX0YAt/oBW5kcuvpLHLSWusWHnHkYU+qO
+      4SdC3bRhdLV9o3u/oCWzmdeKTdqIyNd2yAbb3W1TsD4EsQECQQD6w+vWVKhWbVOj
+      Ky3ZkLCxPcWNUt+7OIzDA1OLKhdhe44hIoRMfDT6iLK3sJTSjgOv0OFTfsdOqh5y
+      ZqYp/CTpAkEA8CQFKkAYt4qG1lKMPsU/Tme0/Z24VozDRnyw7r663f0De+25kXGY
+      PSBiOHYcAE6poYQEtR/leLTSaG3YZm7hqQJBAOLAWLg1Uwbb0v4/pDUQlgWfQsy4
+      /KAx0W7hyiCTzhKTBAFIUfNLeSh2hYx+ewQt8H2B1s6GXDjwsZlm4qgiXUkCQQC9
+      B12ZeIL8V2r0Yl5LOvEuQqxRx0lHt94vKhAMns5x16xabTLZrlVsKIWodDBufX1B
+      yq359XWooo3N7kmduEKhAkEAppzKLuVtX1XPL4VZBex/M2ewngjkSg964BvxIBwv
+      bFzeSqlMpnbEoOJ9hhx6CsP6Y7V19DRRXi0XgwcAjHLz8g==
+      -----END RSA PRIVATE KEY-----
+    KEY
     let(:parent_key) { OpenSSL::PKey::RSA.new(parent_serialized_key) }
     # -----BEGIN PUBLIC KEY-----
     # MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDrOvW1UArKoUOg54XWXcTD3jU0
@@ -63,116 +65,116 @@ KEY
       )
     }
 
-    let(:legacy_format_comment_xml_alice) { <<-XML }
-<XML>
-  <post>
-    <comment>
-      <guid>e21589b0b41101333b870f77ba60fa73</guid>
-      <parent_guid>9e269ae0b41201333b8c0f77ba60fa73</parent_guid>
-      <author_signature>XU5X1uqTh8SY6JMG9uhEVR5Rg7FURV6lpRwl/HYOu6DJ3Hd9tpA2aSFFibUxxsMgJXKNrrc5SykrrEdTiQoEei+j0QqZf3B5R7r84qgK7M46KazwIpqRPwVl2MdA/0DdQyYJLA/oavNj1nwll9vtR87M7e/C94qG6P+iQTMBQzo=</author_signature>
-      <parent_author_signature/>
-      <text>this is a very informative comment</text>
-      <diaspora_handle>alice@pod-a.org</diaspora_handle>
-    </comment>
-  </post>
-</XML>
-XML
-    let(:new_format_comment_xml_alice) { <<-XML }
-<comment>
-  <author>alice@pod-a.org</author>
-  <guid>e21589b0b41101333b870f77ba60fa73</guid>
-  <parent_guid>9e269ae0b41201333b8c0f77ba60fa73</parent_guid>
-  <text>this is a very informative comment</text>
-  <author_signature>SQbLeqsEpFmSl74G1fFJXKQcsq6jp5B2ZjmfEOF/LbBccYP2oZEyEqOq18K3Fa71OYTp6Nddb38hCmHWWHvnGUltGfxKBnQ0WHafJUi40VM4VmeRoU8cac6m+1hslwe5SNmK6oh47EV3mRCXlgGGjLIrw7iEwjKL2g9x1gkNp2s=</author_signature>
-  <parent_author_signature/>
-</comment>
-XML
-    let(:new_data_comment_xml_alice) { <<-XML }
-<comment>
-  <author>alice@pod-a.org</author>
-  <guid>e21589b0b41101333b870f77ba60fa73</guid>
-  <parent_guid>9e269ae0b41201333b8c0f77ba60fa73</parent_guid>
-  <text>this is a very informative comment</text>
-  <new_data>foobar</new_data>
-  <author_signature>SFYXSvCX/DhTFiOUALp2Nf1kfNkGKXrnoBPikAyhaIogGydVBm+8tIlu1U/vsnpyKO3yfC3JReJ00/UBd4J16VO1IxStntq8NUqbSv4me5A/6kdK9Xg6eYbXrqQGm8fUQ5Xuh2UzeB71p7SVySXX3OZHVe0dvHCxH/lsfSDpEjc=</author_signature>
-  <parent_author_signature/>
-</comment>
-XML
+    let(:legacy_format_comment_xml_alice) { <<~XML }
+      <XML>
+        <post>
+          <comment>
+            <guid>e21589b0b41101333b870f77ba60fa73</guid>
+            <parent_guid>9e269ae0b41201333b8c0f77ba60fa73</parent_guid>
+            <author_signature>XU5X1uqTh8SY6JMG9uhEVR5Rg7FURV6lpRwl/HYOu6DJ3Hd9tpA2aSFFibUxxsMgJXKNrrc5SykrrEdTiQoEei+j0QqZf3B5R7r84qgK7M46KazwIpqRPwVl2MdA/0DdQyYJLA/oavNj1nwll9vtR87M7e/C94qG6P+iQTMBQzo=</author_signature>
+            <parent_author_signature/>
+            <text>this is a very informative comment</text>
+            <diaspora_handle>alice@pod-a.org</diaspora_handle>
+          </comment>
+        </post>
+      </XML>
+    XML
+    let(:new_format_comment_xml_alice) { <<~XML }
+      <comment>
+        <author>alice@pod-a.org</author>
+        <guid>e21589b0b41101333b870f77ba60fa73</guid>
+        <parent_guid>9e269ae0b41201333b8c0f77ba60fa73</parent_guid>
+        <text>this is a very informative comment</text>
+        <author_signature>SQbLeqsEpFmSl74G1fFJXKQcsq6jp5B2ZjmfEOF/LbBccYP2oZEyEqOq18K3Fa71OYTp6Nddb38hCmHWWHvnGUltGfxKBnQ0WHafJUi40VM4VmeRoU8cac6m+1hslwe5SNmK6oh47EV3mRCXlgGGjLIrw7iEwjKL2g9x1gkNp2s=</author_signature>
+        <parent_author_signature/>
+      </comment>
+    XML
+    let(:new_data_comment_xml_alice) { <<~XML }
+      <comment>
+        <author>alice@pod-a.org</author>
+        <guid>e21589b0b41101333b870f77ba60fa73</guid>
+        <parent_guid>9e269ae0b41201333b8c0f77ba60fa73</parent_guid>
+        <text>this is a very informative comment</text>
+        <new_data>foobar</new_data>
+        <author_signature>SFYXSvCX/DhTFiOUALp2Nf1kfNkGKXrnoBPikAyhaIogGydVBm+8tIlu1U/vsnpyKO3yfC3JReJ00/UBd4J16VO1IxStntq8NUqbSv4me5A/6kdK9Xg6eYbXrqQGm8fUQ5Xuh2UzeB71p7SVySXX3OZHVe0dvHCxH/lsfSDpEjc=</author_signature>
+        <parent_author_signature/>
+      </comment>
+    XML
 
-    let(:legacy_format_comment_xml_bob) { <<-XML }
-<XML>
-  <post>
-    <comment>
-      <guid>e21589b0b41101333b870f77ba60fa73</guid>
-      <parent_guid>9e269ae0b41201333b8c0f77ba60fa73</parent_guid>
-      <text>this is a very informative comment</text>
-      <diaspora_handle>alice@pod-a.org</diaspora_handle>
-      <author_signature>XU5X1uqTh8SY6JMG9uhEVR5Rg7FURV6lpRwl/HYOu6DJ3Hd9tpA2aSFFibUxxsMgJXKNrrc5SykrrEdTiQoEei+j0QqZf3B5R7r84qgK7M46KazwIpqRPwVl2MdA/0DdQyYJLA/oavNj1nwll9vtR87M7e/C94qG6P+iQTMBQzo=</author_signature>
-      <parent_author_signature>QqWSdwpb+/dcJUxuKKVe7aiz1NivXzlIdWZ71xyrxnhFxFYd+7EIittyTcp1cVehjg96pwDbn++P/rWyCffqenWu025DHvUfSmQkC93Z0dX6r3OIUlZqwEggtOdbunybiE++F3BVsGt5wC4YbAESB5ZFuhFVhBXh1X+EaZ/qoKo=</parent_author_signature>
-    </comment>
-  </post>
-</XML>
-XML
-    let(:legacy_order_new_format_comment_xml_bob) { <<-XML }
-<comment>
-  <guid>e21589b0b41101333b870f77ba60fa73</guid>
-  <parent_guid>9e269ae0b41201333b8c0f77ba60fa73</parent_guid>
-  <text>this is a very informative comment</text>
-  <author>alice@pod-a.org</author>
-  <author_signature>XU5X1uqTh8SY6JMG9uhEVR5Rg7FURV6lpRwl/HYOu6DJ3Hd9tpA2aSFFibUxxsMgJXKNrrc5SykrrEdTiQoEei+j0QqZf3B5R7r84qgK7M46KazwIpqRPwVl2MdA/0DdQyYJLA/oavNj1nwll9vtR87M7e/C94qG6P+iQTMBQzo=</author_signature>
-  <parent_author_signature>QqWSdwpb+/dcJUxuKKVe7aiz1NivXzlIdWZ71xyrxnhFxFYd+7EIittyTcp1cVehjg96pwDbn++P/rWyCffqenWu025DHvUfSmQkC93Z0dX6r3OIUlZqwEggtOdbunybiE++F3BVsGt5wC4YbAESB5ZFuhFVhBXh1X+EaZ/qoKo=</parent_author_signature>
-</comment>
-XML
-    let(:new_order_legacy_format_comment_xml_bob) { <<-XML }
-<XML>
-  <post>
-    <comment>
-      <diaspora_handle>alice@pod-a.org</diaspora_handle>
-      <guid>e21589b0b41101333b870f77ba60fa73</guid>
-      <parent_guid>9e269ae0b41201333b8c0f77ba60fa73</parent_guid>
-      <text>this is a very informative comment</text>
-      <author_signature>SQbLeqsEpFmSl74G1fFJXKQcsq6jp5B2ZjmfEOF/LbBccYP2oZEyEqOq18K3Fa71OYTp6Nddb38hCmHWWHvnGUltGfxKBnQ0WHafJUi40VM4VmeRoU8cac6m+1hslwe5SNmK6oh47EV3mRCXlgGGjLIrw7iEwjKL2g9x1gkNp2s=</author_signature>
-      <parent_author_signature>hWsagsczmZD6d36d6MFdTt3hKAdnRtupSIU6464G2kkMJ+WlExxMgbF6kWR+jVCBTeKipWCYK3Arnj0YkuIZM9d14bJGVMTsW/ZzNfJ69bXZhsyawI8dPnZnLVydo+hU/XmGJBEuh2TOj9Emq6/HCYiWzPTF5qhYAtyJ1oxJ4Yk=</parent_author_signature>
-    </comment>
-  </post>
-</XML>
-XML
-    let(:new_format_comment_xml_bob) { <<-XML }
-<comment>
-  <author>alice@pod-a.org</author>
-  <guid>e21589b0b41101333b870f77ba60fa73</guid>
-  <parent_guid>9e269ae0b41201333b8c0f77ba60fa73</parent_guid>
-  <text>this is a very informative comment</text>
-  <author_signature>SQbLeqsEpFmSl74G1fFJXKQcsq6jp5B2ZjmfEOF/LbBccYP2oZEyEqOq18K3Fa71OYTp6Nddb38hCmHWWHvnGUltGfxKBnQ0WHafJUi40VM4VmeRoU8cac6m+1hslwe5SNmK6oh47EV3mRCXlgGGjLIrw7iEwjKL2g9x1gkNp2s=</author_signature>
-  <parent_author_signature>hWsagsczmZD6d36d6MFdTt3hKAdnRtupSIU6464G2kkMJ+WlExxMgbF6kWR+jVCBTeKipWCYK3Arnj0YkuIZM9d14bJGVMTsW/ZzNfJ69bXZhsyawI8dPnZnLVydo+hU/XmGJBEuh2TOj9Emq6/HCYiWzPTF5qhYAtyJ1oxJ4Yk=</parent_author_signature>
-</comment>
-XML
-    let(:legacy_format_new_data_comment_xml_bob) { <<-XML }
-<XML>
-  <post>
-    <comment>
-      <diaspora_handle>alice@pod-a.org</diaspora_handle>
-      <guid>e21589b0b41101333b870f77ba60fa73</guid>
-      <parent_guid>9e269ae0b41201333b8c0f77ba60fa73</parent_guid>
-      <text>this is a very informative comment</text>
-      <new_data>foobar</new_data>
-      <author_signature>SFYXSvCX/DhTFiOUALp2Nf1kfNkGKXrnoBPikAyhaIogGydVBm+8tIlu1U/vsnpyKO3yfC3JReJ00/UBd4J16VO1IxStntq8NUqbSv4me5A/6kdK9Xg6eYbXrqQGm8fUQ5Xuh2UzeB71p7SVySXX3OZHVe0dvHCxH/lsfSDpEjc=</author_signature>
-      <parent_author_signature>NxXuEUVeXwUMR77osIbaNlp2oB3bpl8rBEFgQoO6cnoN5ewDbiGADK0x6EhcmJptjwhGVcZiNJNpq7k3/pjJtKaH++3ToCAtcuZoIKwPDsneLnjPhVjE2GXM1TiZKwoHrq41qSp/8Vl5UPbtC6sPiOzIvPKaILXUG8XCiVWuB0M=</parent_author_signature>
-    </comment>
-  </post>
-</XML>
-XML
-    let(:new_data_comment_xml_bob) { <<-XML }
-<comment>
-  <author>alice@pod-a.org</author>
-  <guid>e21589b0b41101333b870f77ba60fa73</guid>
-  <parent_guid>9e269ae0b41201333b8c0f77ba60fa73</parent_guid>
-  <text>this is a very informative comment</text>
-  <new_data>foobar</new_data>
-  <author_signature>SFYXSvCX/DhTFiOUALp2Nf1kfNkGKXrnoBPikAyhaIogGydVBm+8tIlu1U/vsnpyKO3yfC3JReJ00/UBd4J16VO1IxStntq8NUqbSv4me5A/6kdK9Xg6eYbXrqQGm8fUQ5Xuh2UzeB71p7SVySXX3OZHVe0dvHCxH/lsfSDpEjc=</author_signature>
-  <parent_author_signature>NxXuEUVeXwUMR77osIbaNlp2oB3bpl8rBEFgQoO6cnoN5ewDbiGADK0x6EhcmJptjwhGVcZiNJNpq7k3/pjJtKaH++3ToCAtcuZoIKwPDsneLnjPhVjE2GXM1TiZKwoHrq41qSp/8Vl5UPbtC6sPiOzIvPKaILXUG8XCiVWuB0M=</parent_author_signature>
-</comment>
-XML
+    let(:legacy_format_comment_xml_bob) { <<~XML }
+      <XML>
+        <post>
+          <comment>
+            <guid>e21589b0b41101333b870f77ba60fa73</guid>
+            <parent_guid>9e269ae0b41201333b8c0f77ba60fa73</parent_guid>
+            <text>this is a very informative comment</text>
+            <diaspora_handle>alice@pod-a.org</diaspora_handle>
+            <author_signature>XU5X1uqTh8SY6JMG9uhEVR5Rg7FURV6lpRwl/HYOu6DJ3Hd9tpA2aSFFibUxxsMgJXKNrrc5SykrrEdTiQoEei+j0QqZf3B5R7r84qgK7M46KazwIpqRPwVl2MdA/0DdQyYJLA/oavNj1nwll9vtR87M7e/C94qG6P+iQTMBQzo=</author_signature>
+            <parent_author_signature>QqWSdwpb+/dcJUxuKKVe7aiz1NivXzlIdWZ71xyrxnhFxFYd+7EIittyTcp1cVehjg96pwDbn++P/rWyCffqenWu025DHvUfSmQkC93Z0dX6r3OIUlZqwEggtOdbunybiE++F3BVsGt5wC4YbAESB5ZFuhFVhBXh1X+EaZ/qoKo=</parent_author_signature>
+          </comment>
+        </post>
+      </XML>
+    XML
+    let(:legacy_order_new_format_comment_xml_bob) { <<~XML }
+      <comment>
+        <guid>e21589b0b41101333b870f77ba60fa73</guid>
+        <parent_guid>9e269ae0b41201333b8c0f77ba60fa73</parent_guid>
+        <text>this is a very informative comment</text>
+        <author>alice@pod-a.org</author>
+        <author_signature>XU5X1uqTh8SY6JMG9uhEVR5Rg7FURV6lpRwl/HYOu6DJ3Hd9tpA2aSFFibUxxsMgJXKNrrc5SykrrEdTiQoEei+j0QqZf3B5R7r84qgK7M46KazwIpqRPwVl2MdA/0DdQyYJLA/oavNj1nwll9vtR87M7e/C94qG6P+iQTMBQzo=</author_signature>
+        <parent_author_signature>QqWSdwpb+/dcJUxuKKVe7aiz1NivXzlIdWZ71xyrxnhFxFYd+7EIittyTcp1cVehjg96pwDbn++P/rWyCffqenWu025DHvUfSmQkC93Z0dX6r3OIUlZqwEggtOdbunybiE++F3BVsGt5wC4YbAESB5ZFuhFVhBXh1X+EaZ/qoKo=</parent_author_signature>
+      </comment>
+    XML
+    let(:new_order_legacy_format_comment_xml_bob) { <<~XML }
+      <XML>
+        <post>
+          <comment>
+            <diaspora_handle>alice@pod-a.org</diaspora_handle>
+            <guid>e21589b0b41101333b870f77ba60fa73</guid>
+            <parent_guid>9e269ae0b41201333b8c0f77ba60fa73</parent_guid>
+            <text>this is a very informative comment</text>
+            <author_signature>SQbLeqsEpFmSl74G1fFJXKQcsq6jp5B2ZjmfEOF/LbBccYP2oZEyEqOq18K3Fa71OYTp6Nddb38hCmHWWHvnGUltGfxKBnQ0WHafJUi40VM4VmeRoU8cac6m+1hslwe5SNmK6oh47EV3mRCXlgGGjLIrw7iEwjKL2g9x1gkNp2s=</author_signature>
+            <parent_author_signature>hWsagsczmZD6d36d6MFdTt3hKAdnRtupSIU6464G2kkMJ+WlExxMgbF6kWR+jVCBTeKipWCYK3Arnj0YkuIZM9d14bJGVMTsW/ZzNfJ69bXZhsyawI8dPnZnLVydo+hU/XmGJBEuh2TOj9Emq6/HCYiWzPTF5qhYAtyJ1oxJ4Yk=</parent_author_signature>
+          </comment>
+        </post>
+      </XML>
+    XML
+    let(:new_format_comment_xml_bob) { <<~XML }
+      <comment>
+        <author>alice@pod-a.org</author>
+        <guid>e21589b0b41101333b870f77ba60fa73</guid>
+        <parent_guid>9e269ae0b41201333b8c0f77ba60fa73</parent_guid>
+        <text>this is a very informative comment</text>
+        <author_signature>SQbLeqsEpFmSl74G1fFJXKQcsq6jp5B2ZjmfEOF/LbBccYP2oZEyEqOq18K3Fa71OYTp6Nddb38hCmHWWHvnGUltGfxKBnQ0WHafJUi40VM4VmeRoU8cac6m+1hslwe5SNmK6oh47EV3mRCXlgGGjLIrw7iEwjKL2g9x1gkNp2s=</author_signature>
+        <parent_author_signature>hWsagsczmZD6d36d6MFdTt3hKAdnRtupSIU6464G2kkMJ+WlExxMgbF6kWR+jVCBTeKipWCYK3Arnj0YkuIZM9d14bJGVMTsW/ZzNfJ69bXZhsyawI8dPnZnLVydo+hU/XmGJBEuh2TOj9Emq6/HCYiWzPTF5qhYAtyJ1oxJ4Yk=</parent_author_signature>
+      </comment>
+    XML
+    let(:legacy_format_new_data_comment_xml_bob) { <<~XML }
+      <XML>
+        <post>
+          <comment>
+            <diaspora_handle>alice@pod-a.org</diaspora_handle>
+            <guid>e21589b0b41101333b870f77ba60fa73</guid>
+            <parent_guid>9e269ae0b41201333b8c0f77ba60fa73</parent_guid>
+            <text>this is a very informative comment</text>
+            <new_data>foobar</new_data>
+            <author_signature>SFYXSvCX/DhTFiOUALp2Nf1kfNkGKXrnoBPikAyhaIogGydVBm+8tIlu1U/vsnpyKO3yfC3JReJ00/UBd4J16VO1IxStntq8NUqbSv4me5A/6kdK9Xg6eYbXrqQGm8fUQ5Xuh2UzeB71p7SVySXX3OZHVe0dvHCxH/lsfSDpEjc=</author_signature>
+            <parent_author_signature>NxXuEUVeXwUMR77osIbaNlp2oB3bpl8rBEFgQoO6cnoN5ewDbiGADK0x6EhcmJptjwhGVcZiNJNpq7k3/pjJtKaH++3ToCAtcuZoIKwPDsneLnjPhVjE2GXM1TiZKwoHrq41qSp/8Vl5UPbtC6sPiOzIvPKaILXUG8XCiVWuB0M=</parent_author_signature>
+          </comment>
+        </post>
+      </XML>
+    XML
+    let(:new_data_comment_xml_bob) { <<~XML }
+      <comment>
+        <author>alice@pod-a.org</author>
+        <guid>e21589b0b41101333b870f77ba60fa73</guid>
+        <parent_guid>9e269ae0b41201333b8c0f77ba60fa73</parent_guid>
+        <text>this is a very informative comment</text>
+        <new_data>foobar</new_data>
+        <author_signature>SFYXSvCX/DhTFiOUALp2Nf1kfNkGKXrnoBPikAyhaIogGydVBm+8tIlu1U/vsnpyKO3yfC3JReJ00/UBd4J16VO1IxStntq8NUqbSv4me5A/6kdK9Xg6eYbXrqQGm8fUQ5Xuh2UzeB71p7SVySXX3OZHVe0dvHCxH/lsfSDpEjc=</author_signature>
+        <parent_author_signature>NxXuEUVeXwUMR77osIbaNlp2oB3bpl8rBEFgQoO6cnoN5ewDbiGADK0x6EhcmJptjwhGVcZiNJNpq7k3/pjJtKaH++3ToCAtcuZoIKwPDsneLnjPhVjE2GXM1TiZKwoHrq41qSp/8Vl5UPbtC6sPiOzIvPKaILXUG8XCiVWuB0M=</parent_author_signature>
+      </comment>
+    XML
 
     # this was used to create the XMLs above
     context "test-data creation" do
diff --git a/spec/lib/diaspora_federation/callbacks_spec.rb b/spec/lib/diaspora_federation/callbacks_spec.rb
index e6adfe8..80e0ff3 100644
--- a/spec/lib/diaspora_federation/callbacks_spec.rb
+++ b/spec/lib/diaspora_federation/callbacks_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Callbacks do
     subject(:callbacks) { Callbacks.new %i[some_event another_event] }
diff --git a/spec/lib/diaspora_federation/discovery/discovery_spec.rb b/spec/lib/diaspora_federation/discovery/discovery_spec.rb
index 7ee024e..d298d04 100644
--- a/spec/lib/diaspora_federation/discovery/discovery_spec.rb
+++ b/spec/lib/diaspora_federation/discovery/discovery_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Discovery::Discovery do
     let(:host_meta_xrd) { Discovery::HostMeta.from_base_url("http://localhost:3000/").to_xml }
diff --git a/spec/lib/diaspora_federation/discovery/h_card_spec.rb b/spec/lib/diaspora_federation/discovery/h_card_spec.rb
index 5644891..5c2da01 100644
--- a/spec/lib/diaspora_federation/discovery/h_card_spec.rb
+++ b/spec/lib/diaspora_federation/discovery/h_card_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Discovery::HCard do
     let(:person) { Fabricate(:person) }
@@ -21,90 +23,90 @@ module DiasporaFederation
       }
     }
 
-    let(:html) { <<-HTML }
-<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
-  <head>
-    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
-    <meta charset="UTF-8" />
-    <title>#{person.full_name}</title>
-  </head>
-  <body>
-    <div id="content">
-      <h1>#{person.full_name}</h1>
-      <div id="content_inner" class="entity_profile vcard author">
-        <h2>User profile</h2>
-        <dl class="entity_uid">
-          <dt>Uid</dt>
-          <dd>
-            <span class="uid">#{person.guid}</span>
-          </dd>
-        </dl>
-        <dl class="entity_nickname">
-          <dt>Nickname</dt>
-          <dd>
-            <span class="nickname">#{person.nickname}</span>
-          </dd>
-        </dl>
-        <dl class="entity_full_name">
-          <dt>Full_name</dt>
-          <dd>
-            <span class="fn">#{person.full_name}</span>
-          </dd>
-        </dl>
-        <dl class="entity_searchable">
-          <dt>Searchable</dt>
-          <dd>
-            <span class="searchable">#{person.searchable}</span>
-          </dd>
-        </dl>
-        <dl class="entity_key">
-          <dt>Key</dt>
-          <dd>
-            <pre class="key">#{person.serialized_public_key}</pre>
-          </dd>
-        </dl>
-        <dl class="entity_first_name">
-          <dt>First_name</dt>
-          <dd>
-            <span class="given_name">#{person.first_name}</span>
-          </dd>
-        </dl>
-        <dl class="entity_family_name">
-          <dt>Family_name</dt>
-          <dd>
-            <span class="family_name">#{person.last_name}</span>
-          </dd>
-        </dl>
-        <dl class="entity_url">
-          <dt>Url</dt>
-          <dd>
-            <a id="pod_location" class="url" rel="me" href="#{person.url}">#{person.url}</a>
-          </dd>
-        </dl>
-        <dl class="entity_photo">
-          <dt>Photo</dt>
-          <dd>
-            <img class="photo avatar" width="300" height="300" src="#{photo_large_url}" />
-          </dd>
-        </dl>
-        <dl class="entity_photo_medium">
-          <dt>Photo_medium</dt>
-          <dd>
-            <img class="photo avatar" width="100" height="100" src="#{photo_medium_url}" />
-          </dd>
-        </dl>
-        <dl class="entity_photo_small">
-          <dt>Photo_small</dt>
-          <dd>
-            <img class="photo avatar" width="50" height="50" src="#{photo_small_url}" />
-          </dd>
-        </dl>
-      </div>
-    </div>
-  </body>
-</html>
-HTML
+    let(:html) { <<~HTML }
+      <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd">
+      <html xmlns="http://www.w3.org/1999/xhtml">
+        <head>
+          <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
+          <meta charset="UTF-8" />
+          <title>#{person.full_name}</title>
+        </head>
+        <body>
+          <div id="content">
+            <h1>#{person.full_name}</h1>
+            <div id="content_inner" class="entity_profile vcard author">
+              <h2>User profile</h2>
+              <dl class="entity_uid">
+                <dt>Uid</dt>
+                <dd>
+                  <span class="uid">#{person.guid}</span>
+                </dd>
+              </dl>
+              <dl class="entity_nickname">
+                <dt>Nickname</dt>
+                <dd>
+                  <span class="nickname">#{person.nickname}</span>
+                </dd>
+              </dl>
+              <dl class="entity_full_name">
+                <dt>Full_name</dt>
+                <dd>
+                  <span class="fn">#{person.full_name}</span>
+                </dd>
+              </dl>
+              <dl class="entity_searchable">
+                <dt>Searchable</dt>
+                <dd>
+                  <span class="searchable">#{person.searchable}</span>
+                </dd>
+              </dl>
+              <dl class="entity_key">
+                <dt>Key</dt>
+                <dd>
+                  <pre class="key">#{person.serialized_public_key}</pre>
+                </dd>
+              </dl>
+              <dl class="entity_first_name">
+                <dt>First_name</dt>
+                <dd>
+                  <span class="given_name">#{person.first_name}</span>
+                </dd>
+              </dl>
+              <dl class="entity_family_name">
+                <dt>Family_name</dt>
+                <dd>
+                  <span class="family_name">#{person.last_name}</span>
+                </dd>
+              </dl>
+              <dl class="entity_url">
+                <dt>Url</dt>
+                <dd>
+                  <a id="pod_location" class="url" rel="me" href="#{person.url}">#{person.url}</a>
+                </dd>
+              </dl>
+              <dl class="entity_photo">
+                <dt>Photo</dt>
+                <dd>
+                  <img class="photo avatar" width="300" height="300" src="#{photo_large_url}" />
+                </dd>
+              </dl>
+              <dl class="entity_photo_medium">
+                <dt>Photo_medium</dt>
+                <dd>
+                  <img class="photo avatar" width="100" height="100" src="#{photo_medium_url}" />
+                </dd>
+              </dl>
+              <dl class="entity_photo_small">
+                <dt>Photo_small</dt>
+                <dd>
+                  <img class="photo avatar" width="50" height="50" src="#{photo_small_url}" />
+                </dd>
+              </dl>
+            </div>
+          </div>
+        </body>
+      </html>
+    HTML
 
     let(:string) { "HCard:#{data[:guid]}" }
 
@@ -134,78 +136,78 @@ HTML
       end
 
       it "reads minimal hCard" do
-        minimal_html = <<-HTML
-<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
-  <head>
-    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
-    <meta charset="UTF-8" />
-    <title>#{person.full_name}</title>
-  </head>
-  <body>
-    <div id="content">
-      <h1>#{person.full_name}</h1>
-      <div id="content_inner" class="entity_profile vcard author">
-        <h2>User profile</h2>
-        <dl class="entity_uid">
-          <dt>Uid</dt>
-          <dd>
-            <span class="uid">#{person.guid}</span>
-          </dd>
-        </dl>
-        <dl class="entity_full_name">
-          <dt>Full_name</dt>
-          <dd>
-            <span class="fn">#{person.full_name}</span>
-          </dd>
-        </dl>
-        <dl class="entity_searchable">
-          <dt>Searchable</dt>
-          <dd>
-            <span class="searchable">#{person.searchable}</span>
-          </dd>
-        </dl>
-        <dl class="entity_key">
-          <dt>Key</dt>
-          <dd>
-            <pre class="key">#{person.serialized_public_key}</pre>
-          </dd>
-        </dl>
-        <dl class="entity_first_name">
-          <dt>First_name</dt>
-          <dd>
-            <span class="given_name">#{person.first_name}</span>
-          </dd>
-        </dl>
-        <dl class="entity_family_name">
-          <dt>Family_name</dt>
-          <dd>
-            <span class="family_name">#{person.last_name}</span>
-          </dd>
-        </dl>
-        <dl class="entity_photo">
-          <dt>Photo</dt>
-          <dd>
-            <img class="photo avatar" width="300" height="300" src="#{photo_large_url}" />
-          </dd>
-        </dl>
-        <dl class="entity_photo_medium">
-          <dt>Photo_medium</dt>
-          <dd>
-            <img class="photo avatar" width="100" height="100" src="#{photo_medium_url}" />
-          </dd>
-        </dl>
-        <dl class="entity_photo_small">
-          <dt>Photo_small</dt>
-          <dd>
-            <img class="photo avatar" width="50" height="50" src="#{photo_small_url}" />
-          </dd>
-        </dl>
-      </div>
-    </div>
-  </body>
-</html>
-HTML
+        minimal_html = <<~HTML
+          <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd">
+          <html xmlns="http://www.w3.org/1999/xhtml">
+            <head>
+              <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
+              <meta charset="UTF-8" />
+              <title>#{person.full_name}</title>
+            </head>
+            <body>
+              <div id="content">
+                <h1>#{person.full_name}</h1>
+                <div id="content_inner" class="entity_profile vcard author">
+                  <h2>User profile</h2>
+                  <dl class="entity_uid">
+                    <dt>Uid</dt>
+                    <dd>
+                      <span class="uid">#{person.guid}</span>
+                    </dd>
+                  </dl>
+                  <dl class="entity_full_name">
+                    <dt>Full_name</dt>
+                    <dd>
+                      <span class="fn">#{person.full_name}</span>
+                    </dd>
+                  </dl>
+                  <dl class="entity_searchable">
+                    <dt>Searchable</dt>
+                    <dd>
+                      <span class="searchable">#{person.searchable}</span>
+                    </dd>
+                  </dl>
+                  <dl class="entity_key">
+                    <dt>Key</dt>
+                    <dd>
+                      <pre class="key">#{person.serialized_public_key}</pre>
+                    </dd>
+                  </dl>
+                  <dl class="entity_first_name">
+                    <dt>First_name</dt>
+                    <dd>
+                      <span class="given_name">#{person.first_name}</span>
+                    </dd>
+                  </dl>
+                  <dl class="entity_family_name">
+                    <dt>Family_name</dt>
+                    <dd>
+                      <span class="family_name">#{person.last_name}</span>
+                    </dd>
+                  </dl>
+                  <dl class="entity_photo">
+                    <dt>Photo</dt>
+                    <dd>
+                      <img class="photo avatar" width="300" height="300" src="#{photo_large_url}" />
+                    </dd>
+                  </dl>
+                  <dl class="entity_photo_medium">
+                    <dt>Photo_medium</dt>
+                    <dd>
+                      <img class="photo avatar" width="100" height="100" src="#{photo_medium_url}" />
+                    </dd>
+                  </dl>
+                  <dl class="entity_photo_small">
+                    <dt>Photo_small</dt>
+                    <dd>
+                      <img class="photo avatar" width="50" height="50" src="#{photo_small_url}" />
+                    </dd>
+                  </dl>
+                </div>
+              </div>
+            </body>
+          </html>
+        HTML
 
         hcard = Discovery::HCard.from_html(minimal_html)
         expect(hcard.guid).to eq(person.guid)
@@ -259,11 +261,11 @@ HTML
       end
 
       it "fails if the document is incomplete" do
-        invalid_html = <<-HTML
-<div id="content">
-  <span class="fn">#{person.full_name}</span>
-</div>
-HTML
+        invalid_html = <<~HTML
+          <div id="content">
+            <span class="fn">#{person.full_name}</span>
+          </div>
+        HTML
         expect { Discovery::HCard.from_html(invalid_html) }.to raise_error Discovery::InvalidData
       end
 
diff --git a/spec/lib/diaspora_federation/discovery/host_meta_spec.rb b/spec/lib/diaspora_federation/discovery/host_meta_spec.rb
index aeb6fa6..0db73d5 100644
--- a/spec/lib/diaspora_federation/discovery/host_meta_spec.rb
+++ b/spec/lib/diaspora_federation/discovery/host_meta_spec.rb
@@ -1,12 +1,14 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Discovery::HostMeta do
     let(:base_url) { "https://pod.example.tld/" }
-    let(:xml) { <<-XML }
-<?xml version="1.0" encoding="UTF-8"?>
-<XRD xmlns="http://docs.oasis-open.org/ns/xri/xrd-1.0">
-  <Link rel="lrdd" type="application/xrd+xml" template="#{base_url}.well-known/webfinger.xml?resource={uri}"/>
-</XRD>
-XML
+    let(:xml) { <<~XML }
+      <?xml version="1.0" encoding="UTF-8"?>
+      <XRD xmlns="http://docs.oasis-open.org/ns/xri/xrd-1.0">
+        <Link rel="lrdd" type="application/xrd+xml" template="#{base_url}.well-known/webfinger.xml?resource={uri}"/>
+      </XRD>
+    XML
 
     it "must not create blank instances" do
       expect { Discovery::HostMeta.new }.to raise_error NoMethodError
@@ -40,56 +42,56 @@ XML
       end
 
       it "also reads old-style XML" do
-        historic_xml = <<-XML
-<?xml version="1.0" encoding="UTF-8"?>
-<XRD xmlns="http://docs.oasis-open.org/ns/xri/xrd-1.0">
+        historic_xml = <<~XML
+          <?xml version="1.0" encoding="UTF-8"?>
+          <XRD xmlns="http://docs.oasis-open.org/ns/xri/xrd-1.0">
 
-  <!-- Resource-specific Information -->
+            <!-- Resource-specific Information -->
 
-  <Link rel="lrdd"
-        type="application/xrd+xml"
-        template="#{base_url}webfinger?q={uri}" />
+            <Link rel="lrdd"
+                  type="application/xrd+xml"
+                  template="#{base_url}webfinger?q={uri}" />
 
-</XRD>
-XML
+          </XRD>
+        XML
         hm = Discovery::HostMeta.from_xml(historic_xml)
         expect(hm.webfinger_template_url).to eq("#{base_url}webfinger?q={uri}")
       end
 
       it "also reads friendica/redmatrix XML" do
-        friendica_redmatrix_xml = <<-XML
-<?xml version='1.0' encoding='UTF-8'?>
-<XRD xmlns='http://docs.oasis-open.org/ns/xri/xrd-1.0'
-     xmlns:hm='http://host-meta.net/xrd/1.0'>
+        friendica_redmatrix_xml = <<~XML
+          <?xml version='1.0' encoding='UTF-8'?>
+          <XRD xmlns='http://docs.oasis-open.org/ns/xri/xrd-1.0'
+               xmlns:hm='http://host-meta.net/xrd/1.0'>
 
-    <hm:Host>pod.example.tld</hm:Host>
+              <hm:Host>pod.example.tld</hm:Host>
 
-    <Link rel='lrdd' template='#{base_url}xrd/?uri={uri}' />
-    <Link rel="http://oexchange.org/spec/0.8/rel/resident-target" type="application/xrd+xml"
-        href="https://pod.example.tld/oexchange/xrd" />
+              <Link rel='lrdd' template='#{base_url}xrd/?uri={uri}' />
+              <Link rel="http://oexchange.org/spec/0.8/rel/resident-target" type="application/xrd+xml"
+                  href="https://pod.example.tld/oexchange/xrd" />
 
-</XRD>
+          </XRD>
         XML
         hm = Discovery::HostMeta.from_xml(friendica_redmatrix_xml)
         expect(hm.webfinger_template_url).to eq("#{base_url}xrd/?uri={uri}")
       end
 
       it "fails if the document does not contain a webfinger url" do
-        invalid_xml = <<XML
-<?xml version="1.0" encoding="UTF-8"?>
-<XRD xmlns="http://docs.oasis-open.org/ns/xri/xrd-1.0">
-</XRD>
-XML
+        invalid_xml = <<~XML
+          <?xml version="1.0" encoding="UTF-8"?>
+          <XRD xmlns="http://docs.oasis-open.org/ns/xri/xrd-1.0">
+          </XRD>
+        XML
         expect { Discovery::HostMeta.from_xml(invalid_xml) }.to raise_error Discovery::InvalidData
       end
 
       it "fails if the document contains a malformed webfinger url" do
-        invalid_xml = <<XML
-<?xml version="1.0" encoding="UTF-8"?>
-<XRD xmlns="http://docs.oasis-open.org/ns/xri/xrd-1.0">
-  <Link rel="lrdd" type="application/xrd+xml" template="#{base_url}webfinger?q="/>
-</XRD>
-XML
+        invalid_xml = <<~XML
+          <?xml version="1.0" encoding="UTF-8"?>
+          <XRD xmlns="http://docs.oasis-open.org/ns/xri/xrd-1.0">
+            <Link rel="lrdd" type="application/xrd+xml" template="#{base_url}webfinger?q="/>
+          </XRD>
+        XML
         expect { Discovery::HostMeta.from_xml(invalid_xml) }.to raise_error Discovery::InvalidData
       end
 
diff --git a/spec/lib/diaspora_federation/discovery/web_finger_spec.rb b/spec/lib/diaspora_federation/discovery/web_finger_spec.rb
index fb0a2a4..1818e58 100644
--- a/spec/lib/diaspora_federation/discovery/web_finger_spec.rb
+++ b/spec/lib/diaspora_federation/discovery/web_finger_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Discovery::WebFinger do
     let(:person) { Fabricate(:person) }
@@ -16,85 +18,85 @@ module DiasporaFederation
       }
     }
 
-    let(:xml) { <<-XML }
-<?xml version="1.0" encoding="UTF-8"?>
-<XRD xmlns="http://docs.oasis-open.org/ns/xri/xrd-1.0">
-  <Subject>#{acct}</Subject>
-  <Alias>#{person.alias_url}</Alias>
-  <Link rel="http://microformats.org/profile/hcard" type="text/html" href="#{person.hcard_url}"/>
-  <Link rel="http://joindiaspora.com/seed_location" type="text/html" href="#{person.url}"/>
-  <Link rel="http://webfinger.net/rel/profile-page" type="text/html" href="#{person.profile_url}"/>
-  <Link rel="http://schemas.google.com/g/2010#updates-from" type="application/atom+xml" href="#{person.atom_url}"/>
-  <Link rel="salmon" href="#{person.salmon_url}"/>
-  <Link rel="http://ostatus.org/schema/1.0/subscribe" template="#{person.subscribe_url}"/>
-</XRD>
-XML
+    let(:xml) { <<~XML }
+      <?xml version="1.0" encoding="UTF-8"?>
+      <XRD xmlns="http://docs.oasis-open.org/ns/xri/xrd-1.0">
+        <Subject>#{acct}</Subject>
+        <Alias>#{person.alias_url}</Alias>
+        <Link rel="http://microformats.org/profile/hcard" type="text/html" href="#{person.hcard_url}"/>
+        <Link rel="http://joindiaspora.com/seed_location" type="text/html" href="#{person.url}"/>
+        <Link rel="http://webfinger.net/rel/profile-page" type="text/html" href="#{person.profile_url}"/>
+        <Link rel="http://schemas.google.com/g/2010#updates-from" type="application/atom+xml" href="#{person.atom_url}"/>
+        <Link rel="salmon" href="#{person.salmon_url}"/>
+        <Link rel="http://ostatus.org/schema/1.0/subscribe" template="#{person.subscribe_url}"/>
+      </XRD>
+    XML
 
-    let(:minimal_xml) { <<-XML }
-<?xml version="1.0" encoding="UTF-8"?>
-<XRD xmlns="http://docs.oasis-open.org/ns/xri/xrd-1.0">
-  <Subject>#{acct}</Subject>
-  <Link rel="http://microformats.org/profile/hcard" type="text/html" href="#{person.hcard_url}"/>
-  <Link rel="http://joindiaspora.com/seed_location" type="text/html" href="#{person.url}"/>
-</XRD>
-XML
+    let(:minimal_xml) { <<~XML }
+      <?xml version="1.0" encoding="UTF-8"?>
+      <XRD xmlns="http://docs.oasis-open.org/ns/xri/xrd-1.0">
+        <Subject>#{acct}</Subject>
+        <Link rel="http://microformats.org/profile/hcard" type="text/html" href="#{person.hcard_url}"/>
+        <Link rel="http://joindiaspora.com/seed_location" type="text/html" href="#{person.url}"/>
+      </XRD>
+    XML
 
-    let(:json) { <<-JSON }
-{
-  "subject": "#{acct}",
-  "aliases": [
-    "#{person.alias_url}"
-  ],
-  "links": [
-    {
-      "rel": "http://microformats.org/profile/hcard",
-      "type": "text/html",
-      "href": "#{person.hcard_url}"
-    },
-    {
-      "rel": "http://joindiaspora.com/seed_location",
-      "type": "text/html",
-      "href": "#{person.url}"
-    },
-    {
-      "rel": "http://webfinger.net/rel/profile-page",
-      "type": "text/html",
-      "href": "#{person.profile_url}"
-    },
-    {
-      "rel": "http://schemas.google.com/g/2010#updates-from",
-      "type": "application/atom+xml",
-      "href": "#{person.atom_url}"
-    },
-    {
-      "rel": "salmon",
-      "href": "#{person.salmon_url}"
-    },
-    {
-      "rel": "http://ostatus.org/schema/1.0/subscribe",
-      "template": "http://somehost:3000/people?q={uri}"
-    }
-  ]
-}
-JSON
+    let(:json) { <<~JSON }
+      {
+        "subject": "#{acct}",
+        "aliases": [
+          "#{person.alias_url}"
+        ],
+        "links": [
+          {
+            "rel": "http://microformats.org/profile/hcard",
+            "type": "text/html",
+            "href": "#{person.hcard_url}"
+          },
+          {
+            "rel": "http://joindiaspora.com/seed_location",
+            "type": "text/html",
+            "href": "#{person.url}"
+          },
+          {
+            "rel": "http://webfinger.net/rel/profile-page",
+            "type": "text/html",
+            "href": "#{person.profile_url}"
+          },
+          {
+            "rel": "http://schemas.google.com/g/2010#updates-from",
+            "type": "application/atom+xml",
+            "href": "#{person.atom_url}"
+          },
+          {
+            "rel": "salmon",
+            "href": "#{person.salmon_url}"
+          },
+          {
+            "rel": "http://ostatus.org/schema/1.0/subscribe",
+            "template": "http://somehost:3000/people?q={uri}"
+          }
+        ]
+      }
+    JSON
 
-    let(:minimal_json) { <<-JSON }
-{
-  "subject": "#{acct}",
-  "links": [
-    {
-      "rel": "http://microformats.org/profile/hcard",
-      "type": "text/html",
-      "href": "#{person.hcard_url}"
-    },
-    {
-      "rel": "http://joindiaspora.com/seed_location",
-      "type": "text/html",
-      "href": "#{person.url}"
-    }
-  ]
-}
-JSON
+    let(:minimal_json) { <<~JSON }
+      {
+        "subject": "#{acct}",
+        "links": [
+          {
+            "rel": "http://microformats.org/profile/hcard",
+            "type": "text/html",
+            "href": "#{person.hcard_url}"
+          },
+          {
+            "rel": "http://joindiaspora.com/seed_location",
+            "type": "text/html",
+            "href": "#{person.url}"
+          }
+        ]
+      }
+    JSON
 
     let(:string) { "WebFinger:#{data[:acct_uri]}" }
 
@@ -130,20 +132,20 @@ JSON
         end
 
         it "creates XML document with additional data" do
-          xml_with_additional_data = <<-XML
-<?xml version="1.0" encoding="UTF-8"?>
-<XRD xmlns="http://docs.oasis-open.org/ns/xri/xrd-1.0">
-  <Subject>#{acct}</Subject>
-  <Alias>#{person.alias_url}</Alias>
-  <Alias>#{person.profile_url}</Alias>
-  <Property type="http://webfinger.example/ns/name">Bob Smith</Property>
-  <Link rel="http://microformats.org/profile/hcard" type="text/html" href="#{person.hcard_url}"/>
-  <Link rel="http://joindiaspora.com/seed_location" type="text/html" href="#{person.url}"/>
-  <Link rel="http://portablecontacts.net/spec/1.0" href="https://pod.example.tld/poco/trouble"/>
-  <Link rel="http://webfinger.net/rel/avatar" type="image/jpeg" href="http://localhost:3000/assets/user/default.png"/>
-  <Link rel="http://openid.net/specs/connect/1.0/issuer" href="https://pod.example.tld/"/>
-</XRD>
-XML
+          xml_with_additional_data = <<~XML
+            <?xml version="1.0" encoding="UTF-8"?>
+            <XRD xmlns="http://docs.oasis-open.org/ns/xri/xrd-1.0">
+              <Subject>#{acct}</Subject>
+              <Alias>#{person.alias_url}</Alias>
+              <Alias>#{person.profile_url}</Alias>
+              <Property type="http://webfinger.example/ns/name">Bob Smith</Property>
+              <Link rel="http://microformats.org/profile/hcard" type="text/html" href="#{person.hcard_url}"/>
+              <Link rel="http://joindiaspora.com/seed_location" type="text/html" href="#{person.url}"/>
+              <Link rel="http://portablecontacts.net/spec/1.0" href="https://pod.example.tld/poco/trouble"/>
+              <Link rel="http://webfinger.net/rel/avatar" type="image/jpeg" href="http://localhost:3000/assets/user/default.png"/>
+              <Link rel="http://openid.net/specs/connect/1.0/issuer" href="https://pod.example.tld/"/>
+            </XRD>
+          XML
 
           wf = Discovery::WebFinger.new(minimal_data, additional_data)
           expect(wf.to_xml).to eq(xml_with_additional_data)
@@ -162,43 +164,43 @@ XML
         end
 
         it "creates JSON document with additional data" do
-          json_with_additional_data = <<-JSON
-{
-  "subject": "#{acct}",
-  "aliases": [
-    "#{person.alias_url}",
-    "#{person.profile_url}"
-  ],
-  "properties": {
-    "http://webfinger.example/ns/name": "Bob Smith"
-  },
-  "links": [
-    {
-      "rel": "http://microformats.org/profile/hcard",
-      "type": "text/html",
-      "href": "#{person.hcard_url}"
-    },
-    {
-      "rel": "http://joindiaspora.com/seed_location",
-      "type": "text/html",
-      "href": "#{person.url}"
-    },
-    {
-      "rel": "http://portablecontacts.net/spec/1.0",
-      "href": "https://pod.example.tld/poco/trouble"
-    },
-    {
-      "rel": "http://webfinger.net/rel/avatar",
-      "type": "image/jpeg",
-      "href": "http://localhost:3000/assets/user/default.png"
-    },
-    {
-      "rel": "http://openid.net/specs/connect/1.0/issuer",
-      "href": "https://pod.example.tld/"
-    }
-  ]
-}
-JSON
+          json_with_additional_data = <<~JSON
+            {
+              "subject": "#{acct}",
+              "aliases": [
+                "#{person.alias_url}",
+                "#{person.profile_url}"
+              ],
+              "properties": {
+                "http://webfinger.example/ns/name": "Bob Smith"
+              },
+              "links": [
+                {
+                  "rel": "http://microformats.org/profile/hcard",
+                  "type": "text/html",
+                  "href": "#{person.hcard_url}"
+                },
+                {
+                  "rel": "http://joindiaspora.com/seed_location",
+                  "type": "text/html",
+                  "href": "#{person.url}"
+                },
+                {
+                  "rel": "http://portablecontacts.net/spec/1.0",
+                  "href": "https://pod.example.tld/poco/trouble"
+                },
+                {
+                  "rel": "http://webfinger.net/rel/avatar",
+                  "type": "image/jpeg",
+                  "href": "http://localhost:3000/assets/user/default.png"
+                },
+                {
+                  "rel": "http://openid.net/specs/connect/1.0/issuer",
+                  "href": "https://pod.example.tld/"
+                }
+              ]
+            }
+          JSON
 
           wf = Discovery::WebFinger.new(minimal_data, additional_data)
           expect(JSON.pretty_generate(wf.to_json)).to eq(json_with_additional_data.strip)
@@ -249,50 +251,50 @@ JSON
       end
 
       it "reads friendica XML (two aliases, first with acct)" do
-        friendica_xml = <<-XML
-<?xml version="1.0" encoding="UTF-8"?>
-<XRD xmlns="http://docs.oasis-open.org/ns/xri/xrd-1.0">
+        friendica_xml = <<~XML
+          <?xml version="1.0" encoding="UTF-8"?>
+          <XRD xmlns="http://docs.oasis-open.org/ns/xri/xrd-1.0">
 
-    <Subject>#{acct}</Subject>
-    <Alias>#{acct}</Alias>
-    <Alias>#{person.alias_url}</Alias>
+              <Subject>#{acct}</Subject>
+              <Alias>#{acct}</Alias>
+              <Alias>#{person.alias_url}</Alias>
 
-    <Link rel="http://purl.org/macgirvin/dfrn/1.0"
-          href="#{person.profile_url}" />
-    <Link rel="http://schemas.google.com/g/2010#updates-from"
-          type="application/atom+xml"
-          href="#{person.atom_url}" />
-    <Link rel="http://webfinger.net/rel/profile-page"
-          type="text/html"
-          href="#{person.profile_url}" />
-    <Link rel="http://microformats.org/profile/hcard"
-          type="text/html"
-          href="#{person.hcard_url}" />
-    <Link rel="http://portablecontacts.net/spec/1.0"
-          href="https://pod.example.tld/poco/trouble" />
-    <Link rel="http://webfinger.net/rel/avatar"
-          type="image/jpeg"
-          href="http://localhost:3000/assets/user/default.png" />
-    <Link rel="http://joindiaspora.com/seed_location" type="text/html" href="#{person.url}" />
-    <Link rel="http://joindiaspora.com/guid" type="text/html" href="#{person.guid}" />
-    <Link rel="diaspora-public-key" type="RSA" href="#{public_key_base64}" />
+              <Link rel="http://purl.org/macgirvin/dfrn/1.0"
+                    href="#{person.profile_url}" />
+              <Link rel="http://schemas.google.com/g/2010#updates-from"
+                    type="application/atom+xml"
+                    href="#{person.atom_url}" />
+              <Link rel="http://webfinger.net/rel/profile-page"
+                    type="text/html"
+                    href="#{person.profile_url}" />
+              <Link rel="http://microformats.org/profile/hcard"
+                    type="text/html"
+                    href="#{person.hcard_url}" />
+              <Link rel="http://portablecontacts.net/spec/1.0"
+                    href="https://pod.example.tld/poco/trouble" />
+              <Link rel="http://webfinger.net/rel/avatar"
+                    type="image/jpeg"
+                    href="http://localhost:3000/assets/user/default.png" />
+              <Link rel="http://joindiaspora.com/seed_location" type="text/html" href="#{person.url}" />
+              <Link rel="http://joindiaspora.com/guid" type="text/html" href="#{person.guid}" />
+              <Link rel="diaspora-public-key" type="RSA" href="#{public_key_base64}" />
 
-    <Link rel="salmon"
-          href="#{person.salmon_url}" />
-    <Link rel="http://salmon-protocol.org/ns/salmon-replies"
-          href="https://pod.example.tld/salmon/trouble" />
-    <Link rel="http://salmon-protocol.org/ns/salmon-mention"
-          href="https://pod.example.tld/salmon/trouble/mention" />
-    <Link rel="http://ostatus.org/schema/1.0/subscribe"
-          template="https://pod.example.tld/follow?url={uri}" />
-    <Link rel="magic-public-key"
-          href="data:application/magic-public-key,RSA.abcdef1234567890" />
+              <Link rel="salmon"
+                    href="#{person.salmon_url}" />
+              <Link rel="http://salmon-protocol.org/ns/salmon-replies"
+                    href="https://pod.example.tld/salmon/trouble" />
+              <Link rel="http://salmon-protocol.org/ns/salmon-mention"
+                    href="https://pod.example.tld/salmon/trouble/mention" />
+              <Link rel="http://ostatus.org/schema/1.0/subscribe"
+                    template="https://pod.example.tld/follow?url={uri}" />
+              <Link rel="magic-public-key"
+                    href="data:application/magic-public-key,RSA.abcdef1234567890" />
 
-    <Property xmlns:mk="http://salmon-protocol.org/ns/magic-key"
-          type="http://salmon-protocol.org/ns/magic-key"
-          mk:key_id="1">RSA.abcdef1234567890</Property>
+              <Property xmlns:mk="http://salmon-protocol.org/ns/magic-key"
+                    type="http://salmon-protocol.org/ns/magic-key"
+                    mk:key_id="1">RSA.abcdef1234567890</Property>
 
-</XRD>
+          </XRD>
         XML
 
         wf = Discovery::WebFinger.from_xml(friendica_xml)
@@ -306,35 +308,35 @@ JSON
       end
 
       it "reads redmatrix XML (no alias)" do
-        redmatrix_xml = <<-XML
-<?xml version="1.0" encoding="UTF-8"?>
-<XRD xmlns="http://docs.oasis-open.org/ns/xri/xrd-1.0">
+        redmatrix_xml = <<~XML
+          <?xml version="1.0" encoding="UTF-8"?>
+          <XRD xmlns="http://docs.oasis-open.org/ns/xri/xrd-1.0">
 
-    <Subject>#{person.diaspora_id}</Subject>
+              <Subject>#{person.diaspora_id}</Subject>
 
-    <Link rel="http://schemas.google.com/g/2010#updates-from"
-          type="application/atom+xml"
-          href="#{person.atom_url}" />
-    <Link rel="http://webfinger.net/rel/profile-page"
-          type="text/html"
-          href="#{person.profile_url}" />
-    <Link rel="http://portablecontacts.net/spec/1.0"
-          href="https://pod.example.tld/poco/trouble" />
-    <Link rel="http://webfinger.net/rel/avatar"
-          type="image/jpeg"
-          href="http://localhost:3000/assets/user/default.png" />
-    <Link rel="http://microformats.org/profile/hcard"
-          type="text/html"
-          href="#{person.hcard_url}" />
+              <Link rel="http://schemas.google.com/g/2010#updates-from"
+                    type="application/atom+xml"
+                    href="#{person.atom_url}" />
+              <Link rel="http://webfinger.net/rel/profile-page"
+                    type="text/html"
+                    href="#{person.profile_url}" />
+              <Link rel="http://portablecontacts.net/spec/1.0"
+                    href="https://pod.example.tld/poco/trouble" />
+              <Link rel="http://webfinger.net/rel/avatar"
+                    type="image/jpeg"
+                    href="http://localhost:3000/assets/user/default.png" />
+              <Link rel="http://microformats.org/profile/hcard"
+                    type="text/html"
+                    href="#{person.hcard_url}" />
 
-    <Link rel="magic-public-key"
-          href="data:application/magic-public-key,RSA.abcdef1234567890" />
+              <Link rel="magic-public-key"
+                    href="data:application/magic-public-key,RSA.abcdef1234567890" />
 
-    <Link rel="http://joindiaspora.com/seed_location" type="text/html" href="#{person.url}" />
-    <Link rel="http://joindiaspora.com/guid" type="text/html" href="#{person.guid}" />
-    <Link rel="diaspora-public-key" type="RSA" href="#{public_key_base64}" />
+              <Link rel="http://joindiaspora.com/seed_location" type="text/html" href="#{person.url}" />
+              <Link rel="http://joindiaspora.com/guid" type="text/html" href="#{person.guid}" />
+              <Link rel="diaspora-public-key" type="RSA" href="#{public_key_base64}" />
 
-</XRD>
+          </XRD>
         XML
 
         wf = Discovery::WebFinger.from_xml(redmatrix_xml)
@@ -347,11 +349,11 @@ JSON
       end
 
       it "fails if the document is empty" do
-        invalid_xml = <<-XML
-<?xml version="1.0" encoding="UTF-8"?>
-<XRD xmlns="http://docs.oasis-open.org/ns/xri/xrd-1.0">
-</XRD>
-XML
+        invalid_xml = <<~XML
+          <?xml version="1.0" encoding="UTF-8"?>
+          <XRD xmlns="http://docs.oasis-open.org/ns/xri/xrd-1.0">
+          </XRD>
+        XML
         expect { Discovery::WebFinger.from_xml(invalid_xml) }.to raise_error Discovery::InvalidData
       end
 
diff --git a/spec/lib/diaspora_federation/discovery/xrd_document_spec.rb b/spec/lib/diaspora_federation/discovery/xrd_document_spec.rb
index 3fe8a3b..8b99a23 100644
--- a/spec/lib/diaspora_federation/discovery/xrd_document_spec.rb
+++ b/spec/lib/diaspora_federation/discovery/xrd_document_spec.rb
@@ -1,49 +1,51 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Discovery::XrdDocument do
-    let(:xml) { <<-XML }
-<?xml version="1.0" encoding="UTF-8"?>
-<XRD xmlns="http://docs.oasis-open.org/ns/xri/xrd-1.0">
-  <Expires>2010-01-30T09:30:00Z</Expires>
-  <Subject>http://blog.example.com/article/id/314</Subject>
-  <Alias>http://blog.example.com/cool_new_thing</Alias>
-  <Alias>http://blog.example.com/steve/article/7</Alias>
-  <Property type="http://blgx.example.net/ns/version">1.3</Property>
-  <Property type="http://blgx.example.net/ns/ext"/>
-  <Link rel="author" type="text/html" href="http://blog.example.com/author/steve"/>
-  <Link rel="author" href="http://example.com/author/john"/>
-  <Link rel="copyright" template="http://example.com/copyright?id={uri}"/>
-</XRD>
-XML
+    let(:xml) { <<~XML }
+      <?xml version="1.0" encoding="UTF-8"?>
+      <XRD xmlns="http://docs.oasis-open.org/ns/xri/xrd-1.0">
+        <Expires>2010-01-30T09:30:00Z</Expires>
+        <Subject>http://blog.example.com/article/id/314</Subject>
+        <Alias>http://blog.example.com/cool_new_thing</Alias>
+        <Alias>http://blog.example.com/steve/article/7</Alias>
+        <Property type="http://blgx.example.net/ns/version">1.3</Property>
+        <Property type="http://blgx.example.net/ns/ext"/>
+        <Link rel="author" type="text/html" href="http://blog.example.com/author/steve"/>
+        <Link rel="author" href="http://example.com/author/john"/>
+        <Link rel="copyright" template="http://example.com/copyright?id={uri}"/>
+      </XRD>
+    XML
 
-    let(:json) { <<-JSON }
-{
-  "subject": "http://blog.example.com/article/id/314",
-  "expires": "2010-01-30T09:30:00Z",
-  "aliases": [
-    "http://blog.example.com/cool_new_thing",
-    "http://blog.example.com/steve/article/7"
-  ],
-  "properties": {
-    "http://blgx.example.net/ns/version": "1.3",
-    "http://blgx.example.net/ns/ext": null
-  },
-  "links": [
-    {
-      "rel": "author",
-      "type": "text/html",
-      "href": "http://blog.example.com/author/steve"
-    },
-    {
-      "rel": "author",
-      "href": "http://example.com/author/john"
-    },
-    {
-      "rel": "copyright",
-      "template": "http://example.com/copyright?id={uri}"
-    }
-  ]
-}
-JSON
+    let(:json) { <<~JSON }
+      {
+        "subject": "http://blog.example.com/article/id/314",
+        "expires": "2010-01-30T09:30:00Z",
+        "aliases": [
+          "http://blog.example.com/cool_new_thing",
+          "http://blog.example.com/steve/article/7"
+        ],
+        "properties": {
+          "http://blgx.example.net/ns/version": "1.3",
+          "http://blgx.example.net/ns/ext": null
+        },
+        "links": [
+          {
+            "rel": "author",
+            "type": "text/html",
+            "href": "http://blog.example.com/author/steve"
+          },
+          {
+            "rel": "author",
+            "href": "http://example.com/author/john"
+          },
+          {
+            "rel": "copyright",
+            "template": "http://example.com/copyright?id={uri}"
+          }
+        ]
+      }
+    JSON
 
     let(:data) {
       {
diff --git a/spec/lib/diaspora_federation/entities/account_deletion_spec.rb b/spec/lib/diaspora_federation/entities/account_deletion_spec.rb
index 1de2ecf..1d3fb53 100644
--- a/spec/lib/diaspora_federation/entities/account_deletion_spec.rb
+++ b/spec/lib/diaspora_federation/entities/account_deletion_spec.rb
@@ -1,12 +1,14 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::AccountDeletion do
     let(:data) { Fabricate.attributes_for(:account_deletion_entity) }
 
-    let(:xml) { <<-XML }
-<account_deletion>
-  <author>#{data[:author]}</author>
-</account_deletion>
-XML
+    let(:xml) { <<~XML }
+      <account_deletion>
+        <author>#{data[:author]}</author>
+      </account_deletion>
+    XML
 
     let(:string) { "AccountDeletion:#{data[:author]}" }
 
diff --git a/spec/lib/diaspora_federation/entities/account_migration/signable_spec.rb b/spec/lib/diaspora_federation/entities/account_migration/signable_spec.rb
index 5b6b784..0d150d9 100644
--- a/spec/lib/diaspora_federation/entities/account_migration/signable_spec.rb
+++ b/spec/lib/diaspora_federation/entities/account_migration/signable_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::AccountMigration::Signable do
     let(:entity) { TestAMSignableEntity.new({}) }
diff --git a/spec/lib/diaspora_federation/entities/account_migration_spec.rb b/spec/lib/diaspora_federation/entities/account_migration_spec.rb
index 37852df..cf79218 100644
--- a/spec/lib/diaspora_federation/entities/account_migration_spec.rb
+++ b/spec/lib/diaspora_federation/entities/account_migration_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::AccountMigration do
     let(:old_user) { Fabricate(:user) }
@@ -105,29 +107,29 @@ module DiasporaFederation
         }
       }
 
-      let(:xml) { <<-XML }
-<account_migration>
-  <author>#{data[:author]}</author>
-  <profile>
-    <author>#{data[:profile].author}</author>
-    <full_name>#{data[:profile].full_name}</full_name>
-    <first_name>#{data[:profile].first_name}</first_name>
-    <image_url>#{data[:profile].image_url}</image_url>
-    <image_url_medium>#{data[:profile].image_url}</image_url_medium>
-    <image_url_small>#{data[:profile].image_url}</image_url_small>
-    <bio>#{data[:profile].bio}</bio>
-    <birthday>#{data[:profile].birthday}</birthday>
-    <gender>#{data[:profile].gender}</gender>
-    <location>#{data[:profile].location}</location>
-    <searchable>#{data[:profile].searchable}</searchable>
-    <public>#{data[:profile].public}</public>
-    <nsfw>#{data[:profile].nsfw}</nsfw>
-    <tag_string>#{data[:profile].tag_string}</tag_string>
-  </profile>
-  <signature>#{data[:signature]}</signature>
-  <old_identity>#{data[:old_identity]}</old_identity>
-</account_migration>
-XML
+      let(:xml) { <<~XML }
+        <account_migration>
+          <author>#{data[:author]}</author>
+          <profile>
+            <author>#{data[:profile].author}</author>
+            <full_name>#{data[:profile].full_name}</full_name>
+            <first_name>#{data[:profile].first_name}</first_name>
+            <image_url>#{data[:profile].image_url}</image_url>
+            <image_url_medium>#{data[:profile].image_url}</image_url_medium>
+            <image_url_small>#{data[:profile].image_url}</image_url_small>
+            <bio>#{data[:profile].bio}</bio>
+            <birthday>#{data[:profile].birthday}</birthday>
+            <gender>#{data[:profile].gender}</gender>
+            <location>#{data[:profile].location}</location>
+            <searchable>#{data[:profile].searchable}</searchable>
+            <public>#{data[:profile].public}</public>
+            <nsfw>#{data[:profile].nsfw}</nsfw>
+            <tag_string>#{data[:profile].tag_string}</tag_string>
+          </profile>
+          <signature>#{data[:signature]}</signature>
+          <old_identity>#{data[:old_identity]}</old_identity>
+        </account_migration>
+      XML
 
       it_behaves_like "an account migration entity"
     end
@@ -144,29 +146,29 @@ XML
         }
       }
 
-      let(:xml) { <<-XML }
-<account_migration>
-  <author>#{data[:author]}</author>
-  <profile>
-    <author>#{data[:profile].author}</author>
-    <full_name>#{data[:profile].full_name}</full_name>
-    <first_name>#{data[:profile].first_name}</first_name>
-    <image_url>#{data[:profile].image_url}</image_url>
-    <image_url_medium>#{data[:profile].image_url}</image_url_medium>
-    <image_url_small>#{data[:profile].image_url}</image_url_small>
-    <bio>#{data[:profile].bio}</bio>
-    <birthday>#{data[:profile].birthday}</birthday>
-    <gender>#{data[:profile].gender}</gender>
-    <location>#{data[:profile].location}</location>
-    <searchable>#{data[:profile].searchable}</searchable>
-    <public>#{data[:profile].public}</public>
-    <nsfw>#{data[:profile].nsfw}</nsfw>
-    <tag_string>#{data[:profile].tag_string}</tag_string>
-  </profile>
-  <signature>#{data[:signature]}</signature>
-  <old_identity>#{data[:old_identity]}</old_identity>
-</account_migration>
-XML
+      let(:xml) { <<~XML }
+        <account_migration>
+          <author>#{data[:author]}</author>
+          <profile>
+            <author>#{data[:profile].author}</author>
+            <full_name>#{data[:profile].full_name}</full_name>
+            <first_name>#{data[:profile].first_name}</first_name>
+            <image_url>#{data[:profile].image_url}</image_url>
+            <image_url_medium>#{data[:profile].image_url}</image_url_medium>
+            <image_url_small>#{data[:profile].image_url}</image_url_small>
+            <bio>#{data[:profile].bio}</bio>
+            <birthday>#{data[:profile].birthday}</birthday>
+            <gender>#{data[:profile].gender}</gender>
+            <location>#{data[:profile].location}</location>
+            <searchable>#{data[:profile].searchable}</searchable>
+            <public>#{data[:profile].public}</public>
+            <nsfw>#{data[:profile].nsfw}</nsfw>
+            <tag_string>#{data[:profile].tag_string}</tag_string>
+          </profile>
+          <signature>#{data[:signature]}</signature>
+          <old_identity>#{data[:old_identity]}</old_identity>
+        </account_migration>
+      XML
 
       it_behaves_like "an account migration entity"
     end
@@ -182,28 +184,28 @@ XML
         }
       }
 
-      let(:xml) { <<-XML }
-<account_migration>
-  <author>#{data[:author]}</author>
-  <profile>
-    <author>#{data[:profile].author}</author>
-    <full_name>#{data[:profile].full_name}</full_name>
-    <first_name>#{data[:profile].first_name}</first_name>
-    <image_url>#{data[:profile].image_url}</image_url>
-    <image_url_medium>#{data[:profile].image_url}</image_url_medium>
-    <image_url_small>#{data[:profile].image_url}</image_url_small>
-    <bio>#{data[:profile].bio}</bio>
-    <birthday>#{data[:profile].birthday}</birthday>
-    <gender>#{data[:profile].gender}</gender>
-    <location>#{data[:profile].location}</location>
-    <searchable>#{data[:profile].searchable}</searchable>
-    <public>#{data[:profile].public}</public>
-    <nsfw>#{data[:profile].nsfw}</nsfw>
-    <tag_string>#{data[:profile].tag_string}</tag_string>
-  </profile>
-  <signature>#{data[:signature]}</signature>
-</account_migration>
-XML
+      let(:xml) { <<~XML }
+        <account_migration>
+          <author>#{data[:author]}</author>
+          <profile>
+            <author>#{data[:profile].author}</author>
+            <full_name>#{data[:profile].full_name}</full_name>
+            <first_name>#{data[:profile].first_name}</first_name>
+            <image_url>#{data[:profile].image_url}</image_url>
+            <image_url_medium>#{data[:profile].image_url}</image_url_medium>
+            <image_url_small>#{data[:profile].image_url}</image_url_small>
+            <bio>#{data[:profile].bio}</bio>
+            <birthday>#{data[:profile].birthday}</birthday>
+            <gender>#{data[:profile].gender}</gender>
+            <location>#{data[:profile].location}</location>
+            <searchable>#{data[:profile].searchable}</searchable>
+            <public>#{data[:profile].public}</public>
+            <nsfw>#{data[:profile].nsfw}</nsfw>
+            <tag_string>#{data[:profile].tag_string}</tag_string>
+          </profile>
+          <signature>#{data[:signature]}</signature>
+        </account_migration>
+      XML
 
       it "fails validation on construction" do
         expect {
diff --git a/spec/lib/diaspora_federation/entities/comment_spec.rb b/spec/lib/diaspora_federation/entities/comment_spec.rb
index 1263510..042f706 100644
--- a/spec/lib/diaspora_federation/entities/comment_spec.rb
+++ b/spec/lib/diaspora_federation/entities/comment_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::Comment do
     let(:parent) { Fabricate(:post, author: bob) }
@@ -12,41 +14,41 @@ module DiasporaFederation
         ).tap {|hash| add_signatures(hash) }
     }
 
-    let(:xml) { <<-XML }
-<comment>
-  <author>#{data[:author]}</author>
-  <guid>#{data[:guid]}</guid>
-  <parent_guid>#{parent.guid}</parent_guid>
-  <text>#{data[:text]}</text>
-  <created_at>#{data[:created_at].utc.iso8601}</created_at>
-  <edited_at>#{data[:edited_at].utc.iso8601}</edited_at>
-  <author_signature>#{data[:author_signature]}</author_signature>
-  <parent_author_signature>#{data[:parent_author_signature]}</parent_author_signature>
-</comment>
-XML
+    let(:xml) { <<~XML }
+      <comment>
+        <author>#{data[:author]}</author>
+        <guid>#{data[:guid]}</guid>
+        <parent_guid>#{parent.guid}</parent_guid>
+        <text>#{data[:text]}</text>
+        <created_at>#{data[:created_at].utc.iso8601}</created_at>
+        <edited_at>#{data[:edited_at].utc.iso8601}</edited_at>
+        <author_signature>#{data[:author_signature]}</author_signature>
+        <parent_author_signature>#{data[:parent_author_signature]}</parent_author_signature>
+      </comment>
+    XML
 
-    let(:json) { <<-JSON }
-{
-  "entity_type": "comment",
-  "entity_data": {
-    "author": "#{data[:author]}",
-    "guid": "#{data[:guid]}",
-    "parent_guid": "#{parent.guid}",
-    "author_signature": "#{data[:author_signature]}",
-    "text": "#{data[:text]}",
-    "created_at": "#{data[:created_at].iso8601}",
-    "edited_at": "#{data[:edited_at].iso8601}"
-  },
-  "property_order": [
-    "author",
-    "guid",
-    "parent_guid",
-    "text",
-    "created_at",
-    "edited_at"
-  ]
-}
-JSON
+    let(:json) { <<~JSON }
+      {
+        "entity_type": "comment",
+        "entity_data": {
+          "author": "#{data[:author]}",
+          "guid": "#{data[:guid]}",
+          "parent_guid": "#{parent.guid}",
+          "author_signature": "#{data[:author_signature]}",
+          "text": "#{data[:text]}",
+          "created_at": "#{data[:created_at].iso8601}",
+          "edited_at": "#{data[:edited_at].iso8601}"
+        },
+        "property_order": [
+          "author",
+          "guid",
+          "parent_guid",
+          "text",
+          "created_at",
+          "edited_at"
+        ]
+      }
+    JSON
 
     let(:string) { "Comment:#{data[:guid]}:#{parent.guid}" }
 
diff --git a/spec/lib/diaspora_federation/entities/contact_spec.rb b/spec/lib/diaspora_federation/entities/contact_spec.rb
index aea9ef8..7430708 100644
--- a/spec/lib/diaspora_federation/entities/contact_spec.rb
+++ b/spec/lib/diaspora_federation/entities/contact_spec.rb
@@ -1,16 +1,18 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::Contact do
     let(:data) { Fabricate.attributes_for(:contact_entity) }
 
-    let(:xml) { <<-XML }
-<contact>
-  <author>#{data[:author]}</author>
-  <recipient>#{data[:recipient]}</recipient>
-  <following>#{data[:following]}</following>
-  <sharing>#{data[:sharing]}</sharing>
-  <blocking>#{data[:blocking]}</blocking>
-</contact>
-XML
+    let(:xml) { <<~XML }
+      <contact>
+        <author>#{data[:author]}</author>
+        <recipient>#{data[:recipient]}</recipient>
+        <following>#{data[:following]}</following>
+        <sharing>#{data[:sharing]}</sharing>
+        <blocking>#{data[:blocking]}</blocking>
+      </contact>
+    XML
 
     let(:string) { "Contact:#{data[:author]}:#{data[:recipient]}" }
 
diff --git a/spec/lib/diaspora_federation/entities/conversation_spec.rb b/spec/lib/diaspora_federation/entities/conversation_spec.rb
index 0c263b0..9522873 100644
--- a/spec/lib/diaspora_federation/entities/conversation_spec.rb
+++ b/spec/lib/diaspora_federation/entities/conversation_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::Conversation do
     let(:parent) { Fabricate(:conversation, author: bob) }
@@ -27,16 +29,16 @@ module DiasporaFederation
       )
     }
 
-    let(:xml) { <<-XML }
-<conversation>
-  <author>#{data[:author]}</author>
-  <guid>#{parent.guid}</guid>
-  <subject>#{data[:subject]}</subject>
-  <created_at>#{data[:created_at].utc.iso8601}</created_at>
-  <participants>#{data[:participants]}</participants>
-#{data[:messages].map {|a| indent(a.to_xml.to_s, 2) }.join("\n")}
-</conversation>
-XML
+    let(:xml) { <<~XML }
+      <conversation>
+        <author>#{data[:author]}</author>
+        <guid>#{parent.guid}</guid>
+        <subject>#{data[:subject]}</subject>
+        <created_at>#{data[:created_at].utc.iso8601}</created_at>
+        <participants>#{data[:participants]}</participants>
+      #{data[:messages].map {|a| indent(a.to_xml.to_s, 2) }.join("\n")}
+      </conversation>
+    XML
 
     let(:string) { "Conversation:#{data[:guid]}" }
 
@@ -46,15 +48,15 @@ XML
 
     context "default values" do
       it "allows no nested messages" do
-        minimal_xml = <<-XML
-<conversation>
-  <author>#{data[:author]}</author>
-  <guid>#{parent.guid}</guid>
-  <subject>#{data[:subject]}</subject>
-  <created_at>#{data[:created_at]}</created_at>
-  <participant_handles>#{data[:participants]}</participant_handles>
-</conversation>
-XML
+        minimal_xml = <<~XML
+          <conversation>
+            <author>#{data[:author]}</author>
+            <guid>#{parent.guid}</guid>
+            <subject>#{data[:subject]}</subject>
+            <created_at>#{data[:created_at]}</created_at>
+            <participant_handles>#{data[:participants]}</participant_handles>
+          </conversation>
+        XML
 
         parsed_instance = DiasporaFederation::Salmon::XmlPayload.unpack(Nokogiri::XML(minimal_xml).root)
         expect(parsed_instance.messages).to eq([])
diff --git a/spec/lib/diaspora_federation/entities/embed_spec.rb b/spec/lib/diaspora_federation/entities/embed_spec.rb
index 7b857e4..c019813 100644
--- a/spec/lib/diaspora_federation/entities/embed_spec.rb
+++ b/spec/lib/diaspora_federation/entities/embed_spec.rb
@@ -1,27 +1,29 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::Embed do
     let(:data) { Fabricate.attributes_for(:embed_entity) }
 
-    let(:xml) { <<-XML }
-<embed>
-  <url>#{data[:url]}</url>
-  <title>#{data[:title]}</title>
-  <description>#{data[:description]}</description>
-  <image>#{data[:image]}</image>
-</embed>
-XML
+    let(:xml) { <<~XML }
+      <embed>
+        <url>#{data[:url]}</url>
+        <title>#{data[:title]}</title>
+        <description>#{data[:description]}</description>
+        <image>#{data[:image]}</image>
+      </embed>
+    XML
 
-    let(:json) { <<-JSON }
-{
-  "entity_type": "embed",
-  "entity_data": {
-    "url": "#{data[:url]}",
-    "title": "#{data[:title]}",
-    "description": "#{data[:description]}",
-    "image": "#{data[:image]}"
-  }
-}
-JSON
+    let(:json) { <<~JSON }
+      {
+        "entity_type": "embed",
+        "entity_data": {
+          "url": "#{data[:url]}",
+          "title": "#{data[:title]}",
+          "description": "#{data[:description]}",
+          "image": "#{data[:image]}"
+        }
+      }
+    JSON
 
     let(:string) { "Embed:#{data[:url]}" }
 
diff --git a/spec/lib/diaspora_federation/entities/event_participation_spec.rb b/spec/lib/diaspora_federation/entities/event_participation_spec.rb
index b6c7ce1..b06c5d4 100644
--- a/spec/lib/diaspora_federation/entities/event_participation_spec.rb
+++ b/spec/lib/diaspora_federation/entities/event_participation_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::EventParticipation do
     let(:parent) { Fabricate(:event, author: bob) }
@@ -11,17 +13,17 @@ module DiasporaFederation
       ).tap {|hash| add_signatures(hash) }
     }
 
-    let(:xml) { <<-XML }
-<event_participation>
-  <author>#{data[:author]}</author>
-  <guid>#{data[:guid]}</guid>
-  <parent_guid>#{parent.guid}</parent_guid>
-  <status>#{data[:status]}</status>
-  <edited_at>#{data[:edited_at].utc.iso8601}</edited_at>
-  <author_signature>#{data[:author_signature]}</author_signature>
-  <parent_author_signature>#{data[:parent_author_signature]}</parent_author_signature>
-</event_participation>
-XML
+    let(:xml) { <<~XML }
+      <event_participation>
+        <author>#{data[:author]}</author>
+        <guid>#{data[:guid]}</guid>
+        <parent_guid>#{parent.guid}</parent_guid>
+        <status>#{data[:status]}</status>
+        <edited_at>#{data[:edited_at].utc.iso8601}</edited_at>
+        <author_signature>#{data[:author_signature]}</author_signature>
+        <parent_author_signature>#{data[:parent_author_signature]}</parent_author_signature>
+      </event_participation>
+    XML
 
     let(:string) { "EventParticipation:#{data[:guid]}:#{parent.guid}" }
 
diff --git a/spec/lib/diaspora_federation/entities/event_spec.rb b/spec/lib/diaspora_federation/entities/event_spec.rb
index 29f5e77..78568ef 100644
--- a/spec/lib/diaspora_federation/entities/event_spec.rb
+++ b/spec/lib/diaspora_federation/entities/event_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::Event do
     let(:location) { Fabricate(:location_entity) }
@@ -5,24 +7,24 @@ module DiasporaFederation
       Fabricate.attributes_for(:event_entity).merge(author: alice.diaspora_id, location: location)
     }
 
-    let(:xml) { <<-XML }
-<event>
-  <author>#{data[:author]}</author>
-  <guid>#{data[:guid]}</guid>
-  <edited_at>#{data[:edited_at].utc.iso8601}</edited_at>
-  <summary>#{data[:summary]}</summary>
-  <description>#{data[:description]}</description>
-  <start>#{data[:start].utc.iso8601}</start>
-  <end>#{data[:end].utc.iso8601}</end>
-  <all_day>#{data[:all_day]}</all_day>
-  <timezone>#{data[:timezone]}</timezone>
-  <location>
-    <address>#{location.address}</address>
-    <lat>#{location.lat}</lat>
-    <lng>#{location.lng}</lng>
-  </location>
-</event>
-XML
+    let(:xml) { <<~XML }
+      <event>
+        <author>#{data[:author]}</author>
+        <guid>#{data[:guid]}</guid>
+        <edited_at>#{data[:edited_at].utc.iso8601}</edited_at>
+        <summary>#{data[:summary]}</summary>
+        <description>#{data[:description]}</description>
+        <start>#{data[:start].utc.iso8601}</start>
+        <end>#{data[:end].utc.iso8601}</end>
+        <all_day>#{data[:all_day]}</all_day>
+        <timezone>#{data[:timezone]}</timezone>
+        <location>
+          <address>#{location.address}</address>
+          <lat>#{location.lat}</lat>
+          <lng>#{location.lng}</lng>
+        </location>
+      </event>
+    XML
 
     let(:string) { "Event:#{data[:guid]}" }
 
@@ -32,14 +34,14 @@ XML
 
     context "default values" do
       it "uses default values" do
-        minimal_xml = <<-XML
-<event>
-  <author>#{data[:author]}</author>
-  <guid>#{data[:guid]}</guid>
-  <summary>#{data[:summary]}</summary>
-  <start>#{data[:start].utc.iso8601}</start>
-</event>
-XML
+        minimal_xml = <<~XML
+          <event>
+            <author>#{data[:author]}</author>
+            <guid>#{data[:guid]}</guid>
+            <summary>#{data[:summary]}</summary>
+            <start>#{data[:start].utc.iso8601}</start>
+          </event>
+        XML
 
         parsed_instance = DiasporaFederation::Salmon::XmlPayload.unpack(Nokogiri::XML(minimal_xml).root)
         expect(parsed_instance.end).to be_nil
diff --git a/spec/lib/diaspora_federation/entities/like_spec.rb b/spec/lib/diaspora_federation/entities/like_spec.rb
index 5983c94..307f530 100644
--- a/spec/lib/diaspora_federation/entities/like_spec.rb
+++ b/spec/lib/diaspora_federation/entities/like_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::Like do
     let(:parent) { Fabricate(:post, author: bob) }
@@ -12,38 +14,38 @@ module DiasporaFederation
       ).tap {|hash| add_signatures(hash) }
     }
 
-    let(:xml) { <<-XML }
-<like>
-  <author>#{data[:author]}</author>
-  <guid>#{data[:guid]}</guid>
-  <parent_guid>#{parent.guid}</parent_guid>
-  <parent_type>#{parent.entity_type}</parent_type>
-  <positive>#{data[:positive]}</positive>
-  <author_signature>#{data[:author_signature]}</author_signature>
-  <parent_author_signature>#{data[:parent_author_signature]}</parent_author_signature>
-</like>
-XML
+    let(:xml) { <<~XML }
+      <like>
+        <author>#{data[:author]}</author>
+        <guid>#{data[:guid]}</guid>
+        <parent_guid>#{parent.guid}</parent_guid>
+        <parent_type>#{parent.entity_type}</parent_type>
+        <positive>#{data[:positive]}</positive>
+        <author_signature>#{data[:author_signature]}</author_signature>
+        <parent_author_signature>#{data[:parent_author_signature]}</parent_author_signature>
+      </like>
+    XML
 
-    let(:json) { <<-JSON }
-{
-  "entity_type": "like",
-  "entity_data": {
-    "author": "#{data[:author]}",
-    "guid": "#{data[:guid]}",
-    "parent_guid": "#{parent.guid}",
-    "author_signature": "#{data[:author_signature]}",
-    "parent_type": "#{parent.entity_type}",
-    "positive": #{data[:positive]}
-  },
-  "property_order": [
-    "author",
-    "guid",
-    "parent_guid",
-    "parent_type",
-    "positive"
-  ]
-}
-JSON
+    let(:json) { <<~JSON }
+      {
+        "entity_type": "like",
+        "entity_data": {
+          "author": "#{data[:author]}",
+          "guid": "#{data[:guid]}",
+          "parent_guid": "#{parent.guid}",
+          "author_signature": "#{data[:author_signature]}",
+          "parent_type": "#{parent.entity_type}",
+          "positive": #{data[:positive]}
+        },
+        "property_order": [
+          "author",
+          "guid",
+          "parent_guid",
+          "parent_type",
+          "positive"
+        ]
+      }
+    JSON
 
     let(:string) { "Like:#{data[:guid]}:Post:#{parent.guid}" }
 
@@ -59,11 +61,11 @@ JSON
 
     context "invalid XML" do
       it "raises a ValidationError if the parent_type is missing" do
-        broken_xml = <<-XML
-<like>
-  <parent_guid>#{parent.guid}</parent_guid>
-</like>
-XML
+        broken_xml = <<~XML
+          <like>
+            <parent_guid>#{parent.guid}</parent_guid>
+          </like>
+        XML
 
         expect {
           DiasporaFederation::Entities::Like.from_xml(Nokogiri::XML(broken_xml).root)
@@ -71,11 +73,11 @@ XML
       end
 
       it "raises a ValidationError if the parent_guid is missing" do
-        broken_xml = <<-XML
-<like>
-  <target_type>#{parent.entity_type}</target_type>
-</like>
-XML
+        broken_xml = <<~XML
+          <like>
+            <target_type>#{parent.entity_type}</target_type>
+          </like>
+        XML
 
         expect {
           DiasporaFederation::Entities::Like.from_xml(Nokogiri::XML(broken_xml).root)
diff --git a/spec/lib/diaspora_federation/entities/location_spec.rb b/spec/lib/diaspora_federation/entities/location_spec.rb
index 0ba629e..afae5aa 100644
--- a/spec/lib/diaspora_federation/entities/location_spec.rb
+++ b/spec/lib/diaspora_federation/entities/location_spec.rb
@@ -1,25 +1,27 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::Location do
     let(:data) { Fabricate.attributes_for(:location_entity) }
 
-    let(:xml) { <<-XML }
-<location>
-  <address>#{data[:address]}</address>
-  <lat>#{data[:lat]}</lat>
-  <lng>#{data[:lng]}</lng>
-</location>
-XML
+    let(:xml) { <<~XML }
+      <location>
+        <address>#{data[:address]}</address>
+        <lat>#{data[:lat]}</lat>
+        <lng>#{data[:lng]}</lng>
+      </location>
+    XML
 
-    let(:json) { <<-JSON }
-{
-  "entity_type": "location",
-  "entity_data": {
-    "address": "#{data[:address]}",
-    "lat": "#{data[:lat]}",
-    "lng": "#{data[:lng]}"
-  }
-}
-JSON
+    let(:json) { <<~JSON }
+      {
+        "entity_type": "location",
+        "entity_data": {
+          "address": "#{data[:address]}",
+          "lat": "#{data[:lat]}",
+          "lng": "#{data[:lng]}"
+        }
+      }
+    JSON
 
     let(:string) { "Location" }
 
diff --git a/spec/lib/diaspora_federation/entities/message_spec.rb b/spec/lib/diaspora_federation/entities/message_spec.rb
index d8aa86d..7657b79 100644
--- a/spec/lib/diaspora_federation/entities/message_spec.rb
+++ b/spec/lib/diaspora_federation/entities/message_spec.rb
@@ -1,17 +1,19 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::Message do
     let(:data) { Fabricate.attributes_for(:message_entity, author: alice.diaspora_id) }
 
-    let(:xml) { <<-XML }
-<message>
-  <author>#{data[:author]}</author>
-  <guid>#{data[:guid]}</guid>
-  <text>#{data[:text]}</text>
-  <created_at>#{data[:created_at].utc.iso8601}</created_at>
-  <edited_at>#{data[:edited_at].utc.iso8601}</edited_at>
-  <conversation_guid>#{data[:conversation_guid]}</conversation_guid>
-</message>
-XML
+    let(:xml) { <<~XML }
+      <message>
+        <author>#{data[:author]}</author>
+        <guid>#{data[:guid]}</guid>
+        <text>#{data[:text]}</text>
+        <created_at>#{data[:created_at].utc.iso8601}</created_at>
+        <edited_at>#{data[:edited_at].utc.iso8601}</edited_at>
+        <conversation_guid>#{data[:conversation_guid]}</conversation_guid>
+      </message>
+    XML
 
     let(:string) { "Message:#{data[:guid]}:#{data[:conversation_guid]}" }
 
diff --git a/spec/lib/diaspora_federation/entities/participation_spec.rb b/spec/lib/diaspora_federation/entities/participation_spec.rb
index 819e4a0..00e96aa 100644
--- a/spec/lib/diaspora_federation/entities/participation_spec.rb
+++ b/spec/lib/diaspora_federation/entities/participation_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::Participation do
     let(:parent) { Fabricate(:post, author: bob) }
@@ -10,26 +12,26 @@ module DiasporaFederation
       )
     }
 
-    let(:xml) { <<-XML }
-<participation>
-  <author>#{data[:author]}</author>
-  <guid>#{data[:guid]}</guid>
-  <parent_guid>#{parent.guid}</parent_guid>
-  <parent_type>#{parent.entity_type}</parent_type>
-</participation>
-XML
+    let(:xml) { <<~XML }
+      <participation>
+        <author>#{data[:author]}</author>
+        <guid>#{data[:guid]}</guid>
+        <parent_guid>#{parent.guid}</parent_guid>
+        <parent_type>#{parent.entity_type}</parent_type>
+      </participation>
+    XML
 
-    let(:json) { <<-JSON }
-{
-  "entity_type": "participation",
-  "entity_data": {
-    "author": "#{data[:author]}",
-    "guid": "#{data[:guid]}",
-    "parent_guid": "#{parent.guid}",
-    "parent_type": "#{parent.entity_type}"
-  }
-}
-JSON
+    let(:json) { <<~JSON }
+      {
+        "entity_type": "participation",
+        "entity_data": {
+          "author": "#{data[:author]}",
+          "guid": "#{data[:guid]}",
+          "parent_guid": "#{parent.guid}",
+          "parent_type": "#{parent.entity_type}"
+        }
+      }
+    JSON
 
     let(:string) { "Participation:#{data[:guid]}:Post:#{parent.guid}" }
 
diff --git a/spec/lib/diaspora_federation/entities/person_spec.rb b/spec/lib/diaspora_federation/entities/person_spec.rb
index 615a41e..a75c35f 100644
--- a/spec/lib/diaspora_federation/entities/person_spec.rb
+++ b/spec/lib/diaspora_federation/entities/person_spec.rb
@@ -1,32 +1,34 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::Person do
     let(:data) { Fabricate.attributes_for(:person_entity) }
 
-    let(:xml) { <<-XML }
-<person>
-  <guid>#{data[:guid]}</guid>
-  <author>#{data[:author]}</author>
-  <url>#{data[:url]}</url>
-  <profile>
-    <author>#{data[:profile].author}</author>
-    <edited_at>#{data[:profile].edited_at.utc.iso8601}</edited_at>
-    <full_name>#{data[:profile].full_name}</full_name>
-    <first_name>#{data[:profile].first_name}</first_name>
-    <image_url>#{data[:profile].image_url}</image_url>
-    <image_url_medium>#{data[:profile].image_url}</image_url_medium>
-    <image_url_small>#{data[:profile].image_url}</image_url_small>
-    <bio>#{data[:profile].bio}</bio>
-    <birthday>#{data[:profile].birthday}</birthday>
-    <gender>#{data[:profile].gender}</gender>
-    <location>#{data[:profile].location}</location>
-    <searchable>#{data[:profile].searchable}</searchable>
-    <public>#{data[:profile].public}</public>
-    <nsfw>#{data[:profile].nsfw}</nsfw>
-    <tag_string>#{data[:profile].tag_string}</tag_string>
-  </profile>
-  <exported_key>#{data[:exported_key]}</exported_key>
-</person>
-XML
+    let(:xml) { <<~XML }
+      <person>
+        <guid>#{data[:guid]}</guid>
+        <author>#{data[:author]}</author>
+        <url>#{data[:url]}</url>
+        <profile>
+          <author>#{data[:profile].author}</author>
+          <edited_at>#{data[:profile].edited_at.utc.iso8601}</edited_at>
+          <full_name>#{data[:profile].full_name}</full_name>
+          <first_name>#{data[:profile].first_name}</first_name>
+          <image_url>#{data[:profile].image_url}</image_url>
+          <image_url_medium>#{data[:profile].image_url}</image_url_medium>
+          <image_url_small>#{data[:profile].image_url}</image_url_small>
+          <bio>#{data[:profile].bio}</bio>
+          <birthday>#{data[:profile].birthday}</birthday>
+          <gender>#{data[:profile].gender}</gender>
+          <location>#{data[:profile].location}</location>
+          <searchable>#{data[:profile].searchable}</searchable>
+          <public>#{data[:profile].public}</public>
+          <nsfw>#{data[:profile].nsfw}</nsfw>
+          <tag_string>#{data[:profile].tag_string}</tag_string>
+        </profile>
+        <exported_key>#{data[:exported_key]}</exported_key>
+      </person>
+    XML
 
     let(:string) { "Person:#{data[:guid]}" }
 
diff --git a/spec/lib/diaspora_federation/entities/photo_spec.rb b/spec/lib/diaspora_federation/entities/photo_spec.rb
index 742f3f9..92d55e9 100644
--- a/spec/lib/diaspora_federation/entities/photo_spec.rb
+++ b/spec/lib/diaspora_federation/entities/photo_spec.rb
@@ -1,41 +1,43 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::Photo do
     let(:data) { Fabricate.attributes_for(:photo_entity) }
 
-    let(:xml) { <<-XML }
-<photo>
-  <guid>#{data[:guid]}</guid>
-  <author>#{data[:author]}</author>
-  <public>#{data[:public]}</public>
-  <created_at>#{data[:created_at].utc.iso8601}</created_at>
-  <edited_at>#{data[:edited_at].utc.iso8601}</edited_at>
-  <remote_photo_path>#{data[:remote_photo_path]}</remote_photo_path>
-  <remote_photo_name>#{data[:remote_photo_name]}</remote_photo_name>
-  <text>#{data[:text]}</text>
-  <status_message_guid>#{data[:status_message_guid]}</status_message_guid>
-  <height>#{data[:height]}</height>
-  <width>#{data[:width]}</width>
-</photo>
-XML
+    let(:xml) { <<~XML }
+      <photo>
+        <guid>#{data[:guid]}</guid>
+        <author>#{data[:author]}</author>
+        <public>#{data[:public]}</public>
+        <created_at>#{data[:created_at].utc.iso8601}</created_at>
+        <edited_at>#{data[:edited_at].utc.iso8601}</edited_at>
+        <remote_photo_path>#{data[:remote_photo_path]}</remote_photo_path>
+        <remote_photo_name>#{data[:remote_photo_name]}</remote_photo_name>
+        <text>#{data[:text]}</text>
+        <status_message_guid>#{data[:status_message_guid]}</status_message_guid>
+        <height>#{data[:height]}</height>
+        <width>#{data[:width]}</width>
+      </photo>
+    XML
 
-    let(:json) { <<-JSON }
-{
-  "entity_type": "photo",
-  "entity_data": {
-    "guid": "#{data[:guid]}",
-    "author": "#{data[:author]}",
-    "public": #{data[:public]},
-    "created_at": "#{data[:created_at].utc.iso8601}",
-    "edited_at": "#{data[:edited_at].iso8601}",
-    "remote_photo_path": "#{data[:remote_photo_path]}",
-    "remote_photo_name": "#{data[:remote_photo_name]}",
-    "text": "#{data[:text]}",
-    "status_message_guid": "#{data[:status_message_guid]}",
-    "height": #{data[:height]},
-    "width": #{data[:width]}
-  }
-}
-JSON
+    let(:json) { <<~JSON }
+      {
+        "entity_type": "photo",
+        "entity_data": {
+          "guid": "#{data[:guid]}",
+          "author": "#{data[:author]}",
+          "public": #{data[:public]},
+          "created_at": "#{data[:created_at].utc.iso8601}",
+          "edited_at": "#{data[:edited_at].iso8601}",
+          "remote_photo_path": "#{data[:remote_photo_path]}",
+          "remote_photo_name": "#{data[:remote_photo_name]}",
+          "text": "#{data[:text]}",
+          "status_message_guid": "#{data[:status_message_guid]}",
+          "height": #{data[:height]},
+          "width": #{data[:width]}
+        }
+      }
+    JSON
 
     let(:string) { "Photo:#{data[:guid]}" }
 
@@ -47,18 +49,18 @@ JSON
 
     context "default values" do
       it "uses default values" do
-        minimal_xml = <<-XML
-<photo>
-  <guid>#{data[:guid]}</guid>
-  <author>#{data[:author]}</author>
-  <created_at>#{data[:created_at]}</created_at>
-  <remote_photo_path>#{data[:remote_photo_path]}</remote_photo_path>
-  <remote_photo_name>#{data[:remote_photo_name]}</remote_photo_name>
-  <status_message_guid>#{data[:status_message_guid]}</status_message_guid>
-  <height>#{data[:height]}</height>
-  <width>#{data[:width]}</width>
-</photo>
-XML
+        minimal_xml = <<~XML
+          <photo>
+            <guid>#{data[:guid]}</guid>
+            <author>#{data[:author]}</author>
+            <created_at>#{data[:created_at]}</created_at>
+            <remote_photo_path>#{data[:remote_photo_path]}</remote_photo_path>
+            <remote_photo_name>#{data[:remote_photo_name]}</remote_photo_name>
+            <status_message_guid>#{data[:status_message_guid]}</status_message_guid>
+            <height>#{data[:height]}</height>
+            <width>#{data[:width]}</width>
+          </photo>
+        XML
 
         parsed_instance = DiasporaFederation::Salmon::XmlPayload.unpack(Nokogiri::XML(minimal_xml).root)
         expect(parsed_instance.public).to be_falsey
diff --git a/spec/lib/diaspora_federation/entities/poll_answer_spec.rb b/spec/lib/diaspora_federation/entities/poll_answer_spec.rb
index b16d23e..c17ec04 100644
--- a/spec/lib/diaspora_federation/entities/poll_answer_spec.rb
+++ b/spec/lib/diaspora_federation/entities/poll_answer_spec.rb
@@ -1,23 +1,25 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::PollAnswer do
     let(:data) { Fabricate.attributes_for(:poll_answer_entity) }
 
-    let(:xml) { <<-XML }
-<poll_answer>
-  <guid>#{data[:guid]}</guid>
-  <answer>#{data[:answer]}</answer>
-</poll_answer>
-XML
+    let(:xml) { <<~XML }
+      <poll_answer>
+        <guid>#{data[:guid]}</guid>
+        <answer>#{data[:answer]}</answer>
+      </poll_answer>
+    XML
 
-    let(:json) { <<-JSON }
-{
-  "entity_type": "poll_answer",
-  "entity_data": {
-    "guid": "#{data[:guid]}",
-    "answer": "#{data[:answer]}"
-  }
-}
-JSON
+    let(:json) { <<~JSON }
+      {
+        "entity_type": "poll_answer",
+        "entity_data": {
+          "guid": "#{data[:guid]}",
+          "answer": "#{data[:answer]}"
+        }
+      }
+    JSON
 
     let(:string) { "PollAnswer:#{data[:guid]}" }
 
diff --git a/spec/lib/diaspora_federation/entities/poll_participation_spec.rb b/spec/lib/diaspora_federation/entities/poll_participation_spec.rb
index 424d767..83848b0 100644
--- a/spec/lib/diaspora_federation/entities/poll_participation_spec.rb
+++ b/spec/lib/diaspora_federation/entities/poll_participation_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::PollParticipation do
     let(:parent) { Fabricate(:poll, author: bob) }
@@ -11,35 +13,35 @@ module DiasporaFederation
       ).tap {|hash| add_signatures(hash) }
     }
 
-    let(:xml) { <<-XML }
-<poll_participation>
-  <author>#{data[:author]}</author>
-  <guid>#{data[:guid]}</guid>
-  <parent_guid>#{parent.guid}</parent_guid>
-  <poll_answer_guid>#{data[:poll_answer_guid]}</poll_answer_guid>
-  <author_signature>#{data[:author_signature]}</author_signature>
-  <parent_author_signature>#{data[:parent_author_signature]}</parent_author_signature>
-</poll_participation>
-XML
+    let(:xml) { <<~XML }
+      <poll_participation>
+        <author>#{data[:author]}</author>
+        <guid>#{data[:guid]}</guid>
+        <parent_guid>#{parent.guid}</parent_guid>
+        <poll_answer_guid>#{data[:poll_answer_guid]}</poll_answer_guid>
+        <author_signature>#{data[:author_signature]}</author_signature>
+        <parent_author_signature>#{data[:parent_author_signature]}</parent_author_signature>
+      </poll_participation>
+    XML
 
-    let(:json) { <<-JSON }
-{
-  "entity_type": "poll_participation",
-  "entity_data": {
-    "author": "#{data[:author]}",
-    "guid": "#{data[:guid]}",
-    "parent_guid": "#{parent.guid}",
-    "author_signature": "#{data[:author_signature]}",
-    "poll_answer_guid": "#{data[:poll_answer_guid]}"
-  },
-  "property_order": [
-    "author",
-    "guid",
-    "parent_guid",
-    "poll_answer_guid"
-  ]
-}
-JSON
+    let(:json) { <<~JSON }
+      {
+        "entity_type": "poll_participation",
+        "entity_data": {
+          "author": "#{data[:author]}",
+          "guid": "#{data[:guid]}",
+          "parent_guid": "#{parent.guid}",
+          "author_signature": "#{data[:author_signature]}",
+          "poll_answer_guid": "#{data[:poll_answer_guid]}"
+        },
+        "property_order": [
+          "author",
+          "guid",
+          "parent_guid",
+          "poll_answer_guid"
+        ]
+      }
+    JSON
 
     let(:string) { "PollParticipation:#{data[:guid]}:#{parent.guid}" }
 
diff --git a/spec/lib/diaspora_federation/entities/poll_spec.rb b/spec/lib/diaspora_federation/entities/poll_spec.rb
index 2065785..3478afb 100644
--- a/spec/lib/diaspora_federation/entities/poll_spec.rb
+++ b/spec/lib/diaspora_federation/entities/poll_spec.rb
@@ -1,27 +1,29 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::Poll do
     let(:data) { Fabricate.attributes_for(:poll_entity) }
 
-    let(:xml) { <<-XML }
-<poll>
-  <guid>#{data[:guid]}</guid>
-  <question>#{data[:question]}</question>
-#{data[:poll_answers].map {|a| indent(a.to_xml.to_s, 2) }.join("\n")}
-</poll>
-XML
+    let(:xml) { <<~XML }
+      <poll>
+        <guid>#{data[:guid]}</guid>
+        <question>#{data[:question]}</question>
+      #{data[:poll_answers].map {|a| indent(a.to_xml.to_s, 2) }.join("\n")}
+      </poll>
+    XML
 
-    let(:json) { <<-JSON }
-{
-  "entity_type": "poll",
-  "entity_data": {
-    "guid": "#{data[:guid]}",
-    "question": "#{data[:question]}",
-    "poll_answers": [
-#{data[:poll_answers].map {|a| indent(JSON.pretty_generate(a.to_json), 6) }.join(",\n")}
-    ]
-  }
-}
-JSON
+    let(:json) { <<~JSON }
+      {
+        "entity_type": "poll",
+        "entity_data": {
+          "guid": "#{data[:guid]}",
+          "question": "#{data[:question]}",
+          "poll_answers": [
+      #{data[:poll_answers].map {|a| indent(JSON.pretty_generate(a.to_json), 6) }.join(",\n")}
+          ]
+        }
+      }
+    JSON
 
     let(:string) { "Poll:#{data[:guid]}" }
 
diff --git a/spec/lib/diaspora_federation/entities/profile_spec.rb b/spec/lib/diaspora_federation/entities/profile_spec.rb
index fa42faf..4cc7d59 100644
--- a/spec/lib/diaspora_federation/entities/profile_spec.rb
+++ b/spec/lib/diaspora_federation/entities/profile_spec.rb
@@ -1,49 +1,51 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::Profile do
     let(:data) { Fabricate.attributes_for(:profile_entity) }
 
-    let(:xml) { <<-XML }
-<profile>
-  <author>#{data[:author]}</author>
-  <edited_at>#{data[:edited_at].utc.iso8601}</edited_at>
-  <full_name>#{data[:full_name]}</full_name>
-  <first_name>#{data[:first_name]}</first_name>
-  <image_url>#{data[:image_url]}</image_url>
-  <image_url_medium>#{data[:image_url]}</image_url_medium>
-  <image_url_small>#{data[:image_url]}</image_url_small>
-  <bio>#{data[:bio]}</bio>
-  <birthday>#{data[:birthday]}</birthday>
-  <gender>#{data[:gender]}</gender>
-  <location>#{data[:location]}</location>
-  <searchable>#{data[:searchable]}</searchable>
-  <public>#{data[:public]}</public>
-  <nsfw>#{data[:nsfw]}</nsfw>
-  <tag_string>#{data[:tag_string]}</tag_string>
-</profile>
-XML
+    let(:xml) { <<~XML }
+      <profile>
+        <author>#{data[:author]}</author>
+        <edited_at>#{data[:edited_at].utc.iso8601}</edited_at>
+        <full_name>#{data[:full_name]}</full_name>
+        <first_name>#{data[:first_name]}</first_name>
+        <image_url>#{data[:image_url]}</image_url>
+        <image_url_medium>#{data[:image_url]}</image_url_medium>
+        <image_url_small>#{data[:image_url]}</image_url_small>
+        <bio>#{data[:bio]}</bio>
+        <birthday>#{data[:birthday]}</birthday>
+        <gender>#{data[:gender]}</gender>
+        <location>#{data[:location]}</location>
+        <searchable>#{data[:searchable]}</searchable>
+        <public>#{data[:public]}</public>
+        <nsfw>#{data[:nsfw]}</nsfw>
+        <tag_string>#{data[:tag_string]}</tag_string>
+      </profile>
+    XML
 
-    let(:json) { <<-JSON }
-{
-  "entity_type": "profile",
-  "entity_data": {
-    "author": "#{data[:author]}",
-    "edited_at": "#{data[:edited_at].iso8601}",
-    "full_name": "#{data[:full_name]}",
-    "first_name": "#{data[:first_name]}",
-    "image_url": "#{data[:image_url]}",
-    "image_url_medium": "#{data[:image_url]}",
-    "image_url_small": "#{data[:image_url]}",
-    "bio": "#{data[:bio]}",
-    "birthday": "#{data[:birthday]}",
-    "gender": "#{data[:gender]}",
-    "location": "#{data[:location]}",
-    "searchable": #{data[:searchable]},
-    "public": #{data[:public]},
-    "nsfw": #{data[:nsfw]},
-    "tag_string": "#{data[:tag_string]}"
-  }
-}
-JSON
+    let(:json) { <<~JSON }
+      {
+        "entity_type": "profile",
+        "entity_data": {
+          "author": "#{data[:author]}",
+          "edited_at": "#{data[:edited_at].iso8601}",
+          "full_name": "#{data[:full_name]}",
+          "first_name": "#{data[:first_name]}",
+          "image_url": "#{data[:image_url]}",
+          "image_url_medium": "#{data[:image_url]}",
+          "image_url_small": "#{data[:image_url]}",
+          "bio": "#{data[:bio]}",
+          "birthday": "#{data[:birthday]}",
+          "gender": "#{data[:gender]}",
+          "location": "#{data[:location]}",
+          "searchable": #{data[:searchable]},
+          "public": #{data[:public]},
+          "nsfw": #{data[:nsfw]},
+          "tag_string": "#{data[:tag_string]}"
+        }
+      }
+    JSON
 
     let(:string) { "Profile:#{data[:author]}" }
 
@@ -55,11 +57,11 @@ JSON
 
     context "default values" do
       it "uses default values" do
-        minimal_xml = <<-XML
-<profile>
-  <author>#{data[:author]}</author>
-</profile>
-XML
+        minimal_xml = <<~XML
+          <profile>
+            <author>#{data[:author]}</author>
+          </profile>
+        XML
 
         parsed_instance = DiasporaFederation::Salmon::XmlPayload.unpack(Nokogiri::XML(minimal_xml).root)
         expect(parsed_instance.full_name).to be_nil
diff --git a/spec/lib/diaspora_federation/entities/related_entity_spec.rb b/spec/lib/diaspora_federation/entities/related_entity_spec.rb
index 902eab3..7b02c81 100644
--- a/spec/lib/diaspora_federation/entities/related_entity_spec.rb
+++ b/spec/lib/diaspora_federation/entities/related_entity_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::RelatedEntity do
     let(:data) { Fabricate.attributes_for(:related_entity) }
diff --git a/spec/lib/diaspora_federation/entities/relayable_retraction_spec.rb b/spec/lib/diaspora_federation/entities/relayable_retraction_spec.rb
index 09bfce4..6bf22d6 100644
--- a/spec/lib/diaspora_federation/entities/relayable_retraction_spec.rb
+++ b/spec/lib/diaspora_federation/entities/relayable_retraction_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::RelayableRetraction do
     let(:target) { Fabricate(:comment, author: bob) }
@@ -10,15 +12,15 @@ module DiasporaFederation
     }
     let(:data) { {author: alice.diaspora_id, target_guid: target.guid, target_type: target.entity_type} }
 
-    let(:xml) { <<-XML }
-<relayable_retraction>
-  <parent_author_signature/>
-  <target_guid>#{data[:target_guid]}</target_guid>
-  <target_type>#{data[:target_type]}</target_type>
-  <sender_handle>#{data[:author]}</sender_handle>
-  <target_author_signature/>
-</relayable_retraction>
-XML
+    let(:xml) { <<~XML }
+      <relayable_retraction>
+        <parent_author_signature/>
+        <target_guid>#{data[:target_guid]}</target_guid>
+        <target_type>#{data[:target_type]}</target_type>
+        <sender_handle>#{data[:author]}</sender_handle>
+        <target_author_signature/>
+      </relayable_retraction>
+    XML
 
     describe "#initialize" do
       it "raises because it is not supported anymore" do
diff --git a/spec/lib/diaspora_federation/entities/relayable_spec.rb b/spec/lib/diaspora_federation/entities/relayable_spec.rb
index f80e143..4daa408 100644
--- a/spec/lib/diaspora_federation/entities/relayable_spec.rb
+++ b/spec/lib/diaspora_federation/entities/relayable_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::Relayable do
     let(:author_pkey) { OpenSSL::PKey::RSA.generate(1024) }
@@ -120,17 +122,17 @@ module DiasporaFederation
     end
 
     describe "#to_xml" do
-      let(:expected_xml) { <<-XML }
-<some_relayable>
-  <author>#{author}</author>
-  <guid>#{guid}</guid>
-  <parent_guid>#{parent_guid}</parent_guid>
-  <property>#{property}</property>
-  <new_property>#{new_property}</new_property>
-  <author_signature>aa</author_signature>
-  <parent_author_signature>bb</parent_author_signature>
-</some_relayable>
-XML
+      let(:expected_xml) { <<~XML }
+        <some_relayable>
+          <author>#{author}</author>
+          <guid>#{guid}</guid>
+          <parent_guid>#{parent_guid}</parent_guid>
+          <property>#{property}</property>
+          <new_property>#{new_property}</new_property>
+          <author_signature>aa</author_signature>
+          <parent_author_signature>bb</parent_author_signature>
+        </some_relayable>
+      XML
 
       it "adds new unknown xml elements to the xml again" do
         signature_order = [:author, :guid, :parent_guid, :property, "new_property"]
@@ -159,17 +161,17 @@ XML
       end
 
       it "adds nil properties to xml when needed for signature_order" do
-        expected_xml = <<-XML
-<some_relayable>
-  <author>#{author}</author>
-  <guid>#{guid}</guid>
-  <parent_guid>#{parent_guid}</parent_guid>
-  <property/>
-  <new_property>#{new_property}</new_property>
-  <author_signature>aa</author_signature>
-  <parent_author_signature>bb</parent_author_signature>
-</some_relayable>
-XML
+        expected_xml = <<~XML
+          <some_relayable>
+            <author>#{author}</author>
+            <guid>#{guid}</guid>
+            <parent_guid>#{parent_guid}</parent_guid>
+            <property/>
+            <new_property>#{new_property}</new_property>
+            <author_signature>aa</author_signature>
+            <parent_author_signature>bb</parent_author_signature>
+          </some_relayable>
+        XML
 
         signature_order = [:author, :guid, :parent_guid, :property, "new_property"]
         xml = Entities::SomeRelayable.new(
@@ -180,15 +182,15 @@ XML
       end
 
       it "does not add nil properties to xml when not needed for signature_order" do
-        expected_xml = <<-XML
-<some_relayable>
-  <author>#{author}</author>
-  <guid>#{guid}</guid>
-  <parent_guid>#{parent_guid}</parent_guid>
-  <author_signature>aa</author_signature>
-  <parent_author_signature>bb</parent_author_signature>
-</some_relayable>
-XML
+        expected_xml = <<~XML
+          <some_relayable>
+            <author>#{author}</author>
+            <guid>#{guid}</guid>
+            <parent_guid>#{parent_guid}</parent_guid>
+            <author_signature>aa</author_signature>
+            <parent_author_signature>bb</parent_author_signature>
+          </some_relayable>
+        XML
 
         xml = Entities::SomeRelayable.new(hash_with_fake_signatures.merge(property: nil)).to_xml
 
@@ -281,16 +283,16 @@ XML
       end
 
       it "adds 'false' booleans" do
-        expected_xml = <<-XML
-<test_relayable_with_boolean>
-  <author>#{author}</author>
-  <guid>#{guid}</guid>
-  <parent_guid>#{parent_guid}</parent_guid>
-  <test>false</test>
-  <author_signature>aa</author_signature>
-  <parent_author_signature>bb</parent_author_signature>
-</test_relayable_with_boolean>
-XML
+        expected_xml = <<~XML
+          <test_relayable_with_boolean>
+            <author>#{author}</author>
+            <guid>#{guid}</guid>
+            <parent_guid>#{parent_guid}</parent_guid>
+            <test>false</test>
+            <author_signature>aa</author_signature>
+            <parent_author_signature>bb</parent_author_signature>
+          </test_relayable_with_boolean>
+        XML
 
         xml = Entities::TestRelayableWithBoolean.new(hash_with_fake_signatures.merge(test: false)).to_xml
 
@@ -306,17 +308,17 @@ XML
         end
 
         let(:new_signature_data) { "#{author};#{guid};#{parent_guid};#{new_property};#{property}" }
-        let(:new_xml) { <<-XML }
-<some_relayable>
-  <diaspora_handle>#{author}</diaspora_handle>
-  <guid>#{guid}</guid>
-  <parent_guid>#{parent_guid}</parent_guid>
-  <new_property>#{new_property}</new_property>
-  <property>#{property}</property>
-  <author_signature>#{sign_with_key(author_pkey, new_signature_data)}</author_signature>
-  <parent_author_signature>#{sign_with_key(parent_pkey, new_signature_data)}</parent_author_signature>
-</some_relayable>
-XML
+        let(:new_xml) { <<~XML }
+          <some_relayable>
+            <diaspora_handle>#{author}</diaspora_handle>
+            <guid>#{guid}</guid>
+            <parent_guid>#{parent_guid}</parent_guid>
+            <new_property>#{new_property}</new_property>
+            <property>#{property}</property>
+            <author_signature>#{sign_with_key(author_pkey, new_signature_data)}</author_signature>
+            <parent_author_signature>#{sign_with_key(parent_pkey, new_signature_data)}</parent_author_signature>
+          </some_relayable>
+        XML
 
         it "doesn't drop unknown properties" do
           entity = Entities::SomeRelayable.from_xml(Nokogiri::XML(new_xml).root)
@@ -350,10 +352,10 @@ XML
 
       context "parse invalid XML" do
         it "raises a ValidationError if the parent_guid is missing" do
-          broken_xml = <<-XML
-<some_relayable>
-</some_relayable>
-XML
+          broken_xml = <<~XML
+            <some_relayable>
+            </some_relayable>
+          XML
 
           expect {
             Entities::SomeRelayable.from_xml(Nokogiri::XML(broken_xml).root)
@@ -361,11 +363,11 @@ XML
         end
 
         it "adds the guid to the error message if available" do
-          broken_xml = <<-XML
-<some_relayable>
-  <guid>#{guid}</guid>
-</some_relayable>
-XML
+          broken_xml = <<~XML
+            <some_relayable>
+              <guid>#{guid}</guid>
+            </some_relayable>
+          XML
 
           expect {
             Entities::SomeRelayable.from_xml(Nokogiri::XML(broken_xml).root)
@@ -373,11 +375,11 @@ XML
         end
 
         it "adds the author to the error message if available" do
-          broken_xml = <<-XML
-<some_relayable>
-  <author>#{author}</author>
-</some_relayable>
-XML
+          broken_xml = <<~XML
+            <some_relayable>
+              <author>#{author}</author>
+            </some_relayable>
+          XML
 
           expect {
             Entities::SomeRelayable.from_xml(Nokogiri::XML(broken_xml).root)
diff --git a/spec/lib/diaspora_federation/entities/request_spec.rb b/spec/lib/diaspora_federation/entities/request_spec.rb
index 1826217..0d07035 100644
--- a/spec/lib/diaspora_federation/entities/request_spec.rb
+++ b/spec/lib/diaspora_federation/entities/request_spec.rb
@@ -1,13 +1,15 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::Request do
     let(:data) { {author: Fabricate.sequence(:diaspora_id), recipient: Fabricate.sequence(:diaspora_id)} }
 
-    let(:xml) { <<-XML }
-<request>
-  <sender_handle>#{data[:author]}</sender_handle>
-  <recipient_handle>#{data[:recipient]}</recipient_handle>
-</request>
-XML
+    let(:xml) { <<~XML }
+      <request>
+        <sender_handle>#{data[:author]}</sender_handle>
+        <recipient_handle>#{data[:recipient]}</recipient_handle>
+      </request>
+    XML
 
     describe "#initialize" do
       it "raises because it is not supported anymore" do
diff --git a/spec/lib/diaspora_federation/entities/reshare_spec.rb b/spec/lib/diaspora_federation/entities/reshare_spec.rb
index 7a15a85..61c5a03 100644
--- a/spec/lib/diaspora_federation/entities/reshare_spec.rb
+++ b/spec/lib/diaspora_federation/entities/reshare_spec.rb
@@ -1,30 +1,32 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::Reshare do
     let(:root) { Fabricate(:post, author: bob) }
     let(:data) { Fabricate.attributes_for(:reshare_entity, root_guid: root.guid, root_author: bob.diaspora_id) }
 
-    let(:xml) { <<-XML }
-<reshare>
-  <author>#{data[:author]}</author>
-  <guid>#{data[:guid]}</guid>
-  <created_at>#{data[:created_at].utc.iso8601}</created_at>
-  <root_author>#{data[:root_author]}</root_author>
-  <root_guid>#{data[:root_guid]}</root_guid>
-</reshare>
-XML
+    let(:xml) { <<~XML }
+      <reshare>
+        <author>#{data[:author]}</author>
+        <guid>#{data[:guid]}</guid>
+        <created_at>#{data[:created_at].utc.iso8601}</created_at>
+        <root_author>#{data[:root_author]}</root_author>
+        <root_guid>#{data[:root_guid]}</root_guid>
+      </reshare>
+    XML
 
-    let(:json) { <<-JSON }
-{
-  "entity_type": "reshare",
-  "entity_data": {
-    "author": "#{data[:author]}",
-    "guid": "#{data[:guid]}",
-    "created_at": "#{data[:created_at].utc.iso8601}",
-    "root_author": "#{data[:root_author]}",
-    "root_guid": "#{data[:root_guid]}"
-  }
-}
-JSON
+    let(:json) { <<~JSON }
+      {
+        "entity_type": "reshare",
+        "entity_data": {
+          "author": "#{data[:author]}",
+          "guid": "#{data[:guid]}",
+          "created_at": "#{data[:created_at].utc.iso8601}",
+          "root_author": "#{data[:root_author]}",
+          "root_guid": "#{data[:root_guid]}"
+        }
+      }
+    JSON
 
     let(:string) { "Reshare:#{data[:guid]}:#{data[:root_guid]}" }
 
diff --git a/spec/lib/diaspora_federation/entities/retraction_spec.rb b/spec/lib/diaspora_federation/entities/retraction_spec.rb
index c3d1e9d..b6ec821 100644
--- a/spec/lib/diaspora_federation/entities/retraction_spec.rb
+++ b/spec/lib/diaspora_federation/entities/retraction_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::Retraction do
     let(:target) { Fabricate(:post, author: bob) }
@@ -11,13 +13,13 @@ module DiasporaFederation
       )
     }
 
-    let(:xml) { <<-XML }
-<retraction>
-  <author>#{data[:author]}</author>
-  <target_guid>#{data[:target_guid]}</target_guid>
-  <target_type>#{data[:target_type]}</target_type>
-</retraction>
-XML
+    let(:xml) { <<~XML }
+      <retraction>
+        <author>#{data[:author]}</author>
+        <target_guid>#{data[:target_guid]}</target_guid>
+        <target_type>#{data[:target_type]}</target_type>
+      </retraction>
+    XML
 
     let(:string) { "Retraction:#{data[:target_type]}:#{data[:target_guid]}" }
 
diff --git a/spec/lib/diaspora_federation/entities/signable_spec.rb b/spec/lib/diaspora_federation/entities/signable_spec.rb
index 6ae9e7f..051e52a 100644
--- a/spec/lib/diaspora_federation/entities/signable_spec.rb
+++ b/spec/lib/diaspora_federation/entities/signable_spec.rb
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::Signable do
-    TEST_STRING_VALUE = "abc123".freeze
+    TEST_STRING_VALUE = "abc123"
 
     class TestSignableEntity < Entity
       include Entities::Signable
diff --git a/spec/lib/diaspora_federation/entities/signed_retraction_spec.rb b/spec/lib/diaspora_federation/entities/signed_retraction_spec.rb
index 0547299..d9d9513 100644
--- a/spec/lib/diaspora_federation/entities/signed_retraction_spec.rb
+++ b/spec/lib/diaspora_federation/entities/signed_retraction_spec.rb
@@ -1,17 +1,19 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::SignedRetraction do
     let(:target) { Fabricate(:post, author: alice) }
     let(:target_entity) { Fabricate(:related_entity, author: alice.diaspora_id) }
     let(:data) { {author: alice.diaspora_id, target_guid: target.guid, target_type: target.entity_type} }
 
-    let(:xml) { <<-XML }
-<signed_retraction>
-  <target_guid>#{data[:target_guid]}</target_guid>
-  <target_type>#{data[:target_type]}</target_type>
-  <sender_handle>#{data[:author]}</sender_handle>
-  <target_author_signature/>
-</signed_retraction>
-XML
+    let(:xml) { <<~XML }
+      <signed_retraction>
+        <target_guid>#{data[:target_guid]}</target_guid>
+        <target_type>#{data[:target_type]}</target_type>
+        <sender_handle>#{data[:author]}</sender_handle>
+        <target_author_signature/>
+      </signed_retraction>
+    XML
 
     describe "#initialize" do
       it "raises because it is not supported anymore" do
diff --git a/spec/lib/diaspora_federation/entities/status_message_spec.rb b/spec/lib/diaspora_federation/entities/status_message_spec.rb
index 4fe600a..9424030 100644
--- a/spec/lib/diaspora_federation/entities/status_message_spec.rb
+++ b/spec/lib/diaspora_federation/entities/status_message_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entities::StatusMessage do
     let(:photo1) { Fabricate(:photo_entity, author: alice.diaspora_id) }
@@ -15,105 +17,105 @@ module DiasporaFederation
       )
     }
 
-    let(:xml) { <<-XML }
-<status_message>
-  <author>#{data[:author]}</author>
-  <guid>#{data[:guid]}</guid>
-  <created_at>#{data[:created_at].utc.iso8601}</created_at>
-  <public>#{data[:public]}</public>
-  <provider_display_name>#{data[:provider_display_name]}</provider_display_name>
-  <text>#{data[:text]}</text>
-  <edited_at>#{data[:edited_at].utc.iso8601}</edited_at>
-  <photo>
-    <guid>#{photo1.guid}</guid>
-    <author>#{photo1.author}</author>
-    <public>#{photo1.public}</public>
-    <created_at>#{photo1.created_at.utc.iso8601}</created_at>
-    <edited_at>#{photo1.edited_at.utc.iso8601}</edited_at>
-    <remote_photo_path>#{photo1.remote_photo_path}</remote_photo_path>
-    <remote_photo_name>#{photo1.remote_photo_name}</remote_photo_name>
-    <text>#{photo1.text}</text>
-    <status_message_guid>#{photo1.status_message_guid}</status_message_guid>
-    <height>#{photo1.height}</height>
-    <width>#{photo1.width}</width>
-  </photo>
-  <photo>
-    <guid>#{photo2.guid}</guid>
-    <author>#{photo2.author}</author>
-    <public>#{photo2.public}</public>
-    <created_at>#{photo2.created_at.utc.iso8601}</created_at>
-    <edited_at>#{photo2.edited_at.utc.iso8601}</edited_at>
-    <remote_photo_path>#{photo2.remote_photo_path}</remote_photo_path>
-    <remote_photo_name>#{photo2.remote_photo_name}</remote_photo_name>
-    <text>#{photo2.text}</text>
-    <status_message_guid>#{photo2.status_message_guid}</status_message_guid>
-    <height>#{photo2.height}</height>
-    <width>#{photo2.width}</width>
-  </photo>
-  <location>
-    <address>#{location.address}</address>
-    <lat>#{location.lat}</lat>
-    <lng>#{location.lng}</lng>
-  </location>
-</status_message>
-XML
+    let(:xml) { <<~XML }
+      <status_message>
+        <author>#{data[:author]}</author>
+        <guid>#{data[:guid]}</guid>
+        <created_at>#{data[:created_at].utc.iso8601}</created_at>
+        <public>#{data[:public]}</public>
+        <provider_display_name>#{data[:provider_display_name]}</provider_display_name>
+        <text>#{data[:text]}</text>
+        <edited_at>#{data[:edited_at].utc.iso8601}</edited_at>
+        <photo>
+          <guid>#{photo1.guid}</guid>
+          <author>#{photo1.author}</author>
+          <public>#{photo1.public}</public>
+          <created_at>#{photo1.created_at.utc.iso8601}</created_at>
+          <edited_at>#{photo1.edited_at.utc.iso8601}</edited_at>
+          <remote_photo_path>#{photo1.remote_photo_path}</remote_photo_path>
+          <remote_photo_name>#{photo1.remote_photo_name}</remote_photo_name>
+          <text>#{photo1.text}</text>
+          <status_message_guid>#{photo1.status_message_guid}</status_message_guid>
+          <height>#{photo1.height}</height>
+          <width>#{photo1.width}</width>
+        </photo>
+        <photo>
+          <guid>#{photo2.guid}</guid>
+          <author>#{photo2.author}</author>
+          <public>#{photo2.public}</public>
+          <created_at>#{photo2.created_at.utc.iso8601}</created_at>
+          <edited_at>#{photo2.edited_at.utc.iso8601}</edited_at>
+          <remote_photo_path>#{photo2.remote_photo_path}</remote_photo_path>
+          <remote_photo_name>#{photo2.remote_photo_name}</remote_photo_name>
+          <text>#{photo2.text}</text>
+          <status_message_guid>#{photo2.status_message_guid}</status_message_guid>
+          <height>#{photo2.height}</height>
+          <width>#{photo2.width}</width>
+        </photo>
+        <location>
+          <address>#{location.address}</address>
+          <lat>#{location.lat}</lat>
+          <lng>#{location.lng}</lng>
+        </location>
+      </status_message>
+    XML
 
-    let(:json) { <<-JSON }
-{
-  "entity_type": "status_message",
-  "entity_data": {
-    "author": "#{data[:author]}",
-    "guid": "#{data[:guid]}",
-    "created_at": "#{data[:created_at].utc.iso8601}",
-    "public": #{data[:public]},
-    "provider_display_name": "#{data[:provider_display_name]}",
-    "text": "#{data[:text]}",
-    "edited_at": "#{data[:edited_at].iso8601}",
-    "photos": [
+    let(:json) { <<~JSON }
       {
-        "entity_type": "photo",
+        "entity_type": "status_message",
         "entity_data": {
-          "guid": "#{photo1.guid}",
-          "author": "#{photo1.author}",
-          "public": #{photo1.public},
-          "created_at": "#{photo1.created_at.utc.iso8601}",
-          "edited_at": "#{photo1.edited_at.utc.iso8601}",
-          "remote_photo_path": "#{photo1.remote_photo_path}",
-          "remote_photo_name": "#{photo1.remote_photo_name}",
-          "text": "#{photo1.text}",
-          "status_message_guid": "#{photo1.status_message_guid}",
-          "height": #{photo1.height},
-          "width": #{photo1.width}
-        }
-      },
-      {
-        "entity_type": "photo",
-        "entity_data": {
-          "guid": "#{photo2.guid}",
-          "author": "#{photo2.author}",
-          "public": #{photo2.public},
-          "created_at": "#{photo2.created_at.utc.iso8601}",
-          "edited_at": "#{photo2.edited_at.utc.iso8601}",
-          "remote_photo_path": "#{photo2.remote_photo_path}",
-          "remote_photo_name": "#{photo2.remote_photo_name}",
-          "text": "#{photo2.text}",
-          "status_message_guid": "#{photo2.status_message_guid}",
-          "height": #{photo2.height},
-          "width": #{photo2.width}
+          "author": "#{data[:author]}",
+          "guid": "#{data[:guid]}",
+          "created_at": "#{data[:created_at].utc.iso8601}",
+          "public": #{data[:public]},
+          "provider_display_name": "#{data[:provider_display_name]}",
+          "text": "#{data[:text]}",
+          "edited_at": "#{data[:edited_at].iso8601}",
+          "photos": [
+            {
+              "entity_type": "photo",
+              "entity_data": {
+                "guid": "#{photo1.guid}",
+                "author": "#{photo1.author}",
+                "public": #{photo1.public},
+                "created_at": "#{photo1.created_at.utc.iso8601}",
+                "edited_at": "#{photo1.edited_at.utc.iso8601}",
+                "remote_photo_path": "#{photo1.remote_photo_path}",
+                "remote_photo_name": "#{photo1.remote_photo_name}",
+                "text": "#{photo1.text}",
+                "status_message_guid": "#{photo1.status_message_guid}",
+                "height": #{photo1.height},
+                "width": #{photo1.width}
+              }
+            },
+            {
+              "entity_type": "photo",
+              "entity_data": {
+                "guid": "#{photo2.guid}",
+                "author": "#{photo2.author}",
+                "public": #{photo2.public},
+                "created_at": "#{photo2.created_at.utc.iso8601}",
+                "edited_at": "#{photo2.edited_at.utc.iso8601}",
+                "remote_photo_path": "#{photo2.remote_photo_path}",
+                "remote_photo_name": "#{photo2.remote_photo_name}",
+                "text": "#{photo2.text}",
+                "status_message_guid": "#{photo2.status_message_guid}",
+                "height": #{photo2.height},
+                "width": #{photo2.width}
+              }
+            }
+          ],
+          "location": {
+            "entity_type": "location",
+            "entity_data": {
+              "address": "#{location.address}",
+              "lat": "#{location.lat}",
+              "lng": "#{location.lng}"
+            }
+          }
         }
       }
-    ],
-    "location": {
-      "entity_type": "location",
-      "entity_data": {
-        "address": "#{location.address}",
-        "lat": "#{location.lat}",
-        "lng": "#{location.lng}"
-      }
-    }
-  }
-}
-JSON
+    JSON
 
     let(:string) { "StatusMessage:#{data[:guid]}" }
 
@@ -125,14 +127,14 @@ JSON
 
     context "default values" do
       it "uses default values" do
-        minimal_xml = <<-XML
-<status_message>
-  <author>#{data[:author]}</author>
-  <guid>#{data[:guid]}</guid>
-  <created_at>#{data[:created_at]}</created_at>
-  <text>#{data[:text]}</text>
-</status_message>
-XML
+        minimal_xml = <<~XML
+          <status_message>
+            <author>#{data[:author]}</author>
+            <guid>#{data[:guid]}</guid>
+            <created_at>#{data[:created_at]}</created_at>
+            <text>#{data[:text]}</text>
+          </status_message>
+        XML
 
         parsed_instance = DiasporaFederation::Salmon::XmlPayload.unpack(Nokogiri::XML(minimal_xml).root)
         expect(parsed_instance.photos).to eq([])
diff --git a/spec/lib/diaspora_federation/entity_spec.rb b/spec/lib/diaspora_federation/entity_spec.rb
index 3039338..cd52a27 100644
--- a/spec/lib/diaspora_federation/entity_spec.rb
+++ b/spec/lib/diaspora_federation/entity_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Entity do
     let(:data) { {test1: "asdf", test2: 1234, test3: false, test4: false} }
@@ -202,13 +204,13 @@ module DiasporaFederation
           test2: "qwer",
           test3: true
         )
-        Entities::TestDefaultEntity.from_xml(Nokogiri::XML(<<-XML).root)
-<test_default_entity>
-  <test1>asdf</test1>
-  <test2>qwer</qwer2>
-  <test3>true</qwer3>
-</test_default_entity>
-XML
+        Entities::TestDefaultEntity.from_xml(Nokogiri::XML(<<~XML).root)
+          <test_default_entity>
+            <test1>asdf</test1>
+            <test2>qwer</qwer2>
+            <test3>true</qwer3>
+          </test_default_entity>
+        XML
       end
 
       it "forms .from_hash arguments basing on parse return array" do
@@ -284,38 +286,38 @@ XML
     describe ".from_json" do
       it "parses entity properties from the input JSON data" do
         now = change_time(Time.now.utc)
-        entity_data = <<-JSON
-{
-  "entity_type": "test_complex_entity",
-  "entity_data": {
-    "test1": "abc",
-    "test2": false,
-    "test3": "def",
-    "test4": 123,
-    "test5": "#{now.iso8601}",
-    "test6": {
-      "entity_type": "test_entity",
-      "entity_data": {
-        "test": "nested"
-      }
-    },
-    "multi": [
-      {
-        "entity_type": "other_entity",
-        "entity_data": {
-          "asdf": "01"
-        }
-      },
-      {
-        "entity_type": "other_entity",
-        "entity_data": {
-          "asdf": "02"
-        }
-      }
-    ]
-  }
-}
-JSON
+        entity_data = <<~JSON
+          {
+            "entity_type": "test_complex_entity",
+            "entity_data": {
+              "test1": "abc",
+              "test2": false,
+              "test3": "def",
+              "test4": 123,
+              "test5": "#{now.iso8601}",
+              "test6": {
+                "entity_type": "test_entity",
+                "entity_data": {
+                  "test": "nested"
+                }
+              },
+              "multi": [
+                {
+                  "entity_type": "other_entity",
+                  "entity_data": {
+                    "asdf": "01"
+                  }
+                },
+                {
+                  "entity_type": "other_entity",
+                  "entity_data": {
+                    "asdf": "02"
+                  }
+                }
+              ]
+            }
+          }
+        JSON
 
         entity = Entities::TestComplexEntity.from_json(JSON.parse(entity_data))
         expect(entity).to be_an_instance_of(Entities::TestComplexEntity)
@@ -511,13 +513,13 @@ JSON
       end
 
       it "handles empty xml-element for nested entities" do
-        xml = <<-XML
-<test_nested_entity>
-  <asdf>FDSA</asdf>
-  <test_entity/>
-  <other_entity/>
-</test_nested_entity>
-XML
+        xml = <<~XML
+          <test_nested_entity>
+            <asdf>FDSA</asdf>
+            <test_entity/>
+            <other_entity/>
+          </test_nested_entity>
+        XML
 
         entity = Entities::TestNestedEntity.from_xml(Nokogiri::XML(xml).root)
 
diff --git a/spec/lib/diaspora_federation/federation/diaspora_url_parser_spec.rb b/spec/lib/diaspora_federation/federation/diaspora_url_parser_spec.rb
index 2649d80..dee3354 100644
--- a/spec/lib/diaspora_federation/federation/diaspora_url_parser_spec.rb
+++ b/spec/lib/diaspora_federation/federation/diaspora_url_parser_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Federation::DiasporaUrlParser do
     let(:author) { Fabricate.sequence(:diaspora_id) }
diff --git a/spec/lib/diaspora_federation/federation/fetcher_spec.rb b/spec/lib/diaspora_federation/federation/fetcher_spec.rb
index 51997eb..d1cdd8f 100644
--- a/spec/lib/diaspora_federation/federation/fetcher_spec.rb
+++ b/spec/lib/diaspora_federation/federation/fetcher_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Federation::Fetcher do
     let(:post) { Fabricate(:status_message_entity, public: true) }
diff --git a/spec/lib/diaspora_federation/federation/receiver/private_spec.rb b/spec/lib/diaspora_federation/federation/receiver/private_spec.rb
index e0fbb37..8d9cb6a 100644
--- a/spec/lib/diaspora_federation/federation/receiver/private_spec.rb
+++ b/spec/lib/diaspora_federation/federation/receiver/private_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Federation::Receiver::Private do
     let(:recipient) { 42 }
diff --git a/spec/lib/diaspora_federation/federation/receiver/public_spec.rb b/spec/lib/diaspora_federation/federation/receiver/public_spec.rb
index 9815490..5aa3220 100644
--- a/spec/lib/diaspora_federation/federation/receiver/public_spec.rb
+++ b/spec/lib/diaspora_federation/federation/receiver/public_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Federation::Receiver::Public do
     let(:post) { Fabricate(:status_message_entity) }
diff --git a/spec/lib/diaspora_federation/federation/receiver_spec.rb b/spec/lib/diaspora_federation/federation/receiver_spec.rb
index 5779a37..b5b2d33 100644
--- a/spec/lib/diaspora_federation/federation/receiver_spec.rb
+++ b/spec/lib/diaspora_federation/federation/receiver_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Federation::Receiver do
     let(:sender_key) { OpenSSL::PKey::RSA.generate(1024) }
diff --git a/spec/lib/diaspora_federation/federation/sender/hydra_wrapper_spec.rb b/spec/lib/diaspora_federation/federation/sender/hydra_wrapper_spec.rb
index 66f9698..170729e 100644
--- a/spec/lib/diaspora_federation/federation/sender/hydra_wrapper_spec.rb
+++ b/spec/lib/diaspora_federation/federation/sender/hydra_wrapper_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Federation::Sender::HydraWrapper do
     let(:sender_id) { Fabricate.sequence(:diaspora_id) }
diff --git a/spec/lib/diaspora_federation/federation/sender_spec.rb b/spec/lib/diaspora_federation/federation/sender_spec.rb
index 8f1dce9..0a8e3ad 100644
--- a/spec/lib/diaspora_federation/federation/sender_spec.rb
+++ b/spec/lib/diaspora_federation/federation/sender_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Federation::Sender do
     let(:sender_id) { Fabricate.sequence(:diaspora_id) }
diff --git a/spec/lib/diaspora_federation/http_client_spec.rb b/spec/lib/diaspora_federation/http_client_spec.rb
index 00efe91..5a4c5a7 100644
--- a/spec/lib/diaspora_federation/http_client_spec.rb
+++ b/spec/lib/diaspora_federation/http_client_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe HttpClient do
     describe ".get" do
diff --git a/spec/lib/diaspora_federation/parsers/base_parser_spec.rb b/spec/lib/diaspora_federation/parsers/base_parser_spec.rb
index 1fdf683..17a3c17 100644
--- a/spec/lib/diaspora_federation/parsers/base_parser_spec.rb
+++ b/spec/lib/diaspora_federation/parsers/base_parser_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Parsers::BaseParser do
     describe ".parse" do
diff --git a/spec/lib/diaspora_federation/parsers/json_parser_spec.rb b/spec/lib/diaspora_federation/parsers/json_parser_spec.rb
index 0758395..71beff5 100644
--- a/spec/lib/diaspora_federation/parsers/json_parser_spec.rb
+++ b/spec/lib/diaspora_federation/parsers/json_parser_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Parsers::JsonParser do
     describe ".parse" do
@@ -6,12 +8,12 @@ module DiasporaFederation
 
       it "raises error when the entity class doesn't match the entity_type property" do
         expect {
-          json_parser.parse(JSON.parse(<<-JSON
-{
-  "entity_type": "unknown_entity",
-  "entity_data": {}
-}
-JSON
+          json_parser.parse(JSON.parse(<<~JSON
+            {
+              "entity_type": "unknown_entity",
+              "entity_data": {}
+            }
+          JSON
                                       ))
         }.to raise_error DiasporaFederation::Parsers::BaseParser::InvalidRootNode,
                          "'unknown_entity' can't be parsed by #{entity_class}"
@@ -27,38 +29,38 @@ JSON
 
       it "returns a hash for the correct JSON input" do
         now = change_time(Time.now.utc)
-        json = <<-JSON
-{
-  "entity_type": "test_complex_entity",
-  "entity_data": {
-    "test1": "abc",
-    "test2": false,
-    "test3": "def",
-    "test4": 123,
-    "test5": "#{now.iso8601}",
-    "test6": {
-      "entity_type": "test_entity",
-      "entity_data": {
-        "test": "nested"
-      }
-    },
-    "multi": [
-      {
-        "entity_type": "other_entity",
-        "entity_data": {
-          "asdf": "01"
-        }
-      },
-      {
-        "entity_type": "other_entity",
-        "entity_data": {
-          "asdf": "02"
-        }
-      }
-    ]
-  }
-}
-JSON
+        json = <<~JSON
+          {
+            "entity_type": "test_complex_entity",
+            "entity_data": {
+              "test1": "abc",
+              "test2": false,
+              "test3": "def",
+              "test4": 123,
+              "test5": "#{now.iso8601}",
+              "test6": {
+                "entity_type": "test_entity",
+                "entity_data": {
+                  "test": "nested"
+                }
+              },
+              "multi": [
+                {
+                  "entity_type": "other_entity",
+                  "entity_data": {
+                    "asdf": "01"
+                  }
+                },
+                {
+                  "entity_type": "other_entity",
+                  "entity_data": {
+                    "asdf": "02"
+                  }
+                }
+              ]
+            }
+          }
+        JSON
         hash = json_parser.parse(JSON.parse(json)).first
         expect(hash).to be_a(Hash)
         expect(hash[:test1]).to eq("abc")
@@ -75,17 +77,17 @@ JSON
       end
 
       it "doesn't drop extra properties" do
-        json = <<-JSON.strip
-{
-  "entity_type": "test_default_entity",
-  "entity_data": {
-    "test1": "abc",
-    "test2": false,
-    "test3": "def",
-    "test_new": "new_value"
-  }
-}
-JSON
+        json = <<~JSON.strip
+          {
+            "entity_type": "test_default_entity",
+            "entity_data": {
+              "test1": "abc",
+              "test2": false,
+              "test3": "def",
+              "test_new": "new_value"
+            }
+          }
+        JSON
 
         parsed = Parsers::JsonParser.new(Entities::TestDefaultEntity).parse(JSON.parse(json))
         expect(parsed[0]["test_new"]).to eq("new_value")
diff --git a/spec/lib/diaspora_federation/parsers/relayable_json_parser_spec.rb b/spec/lib/diaspora_federation/parsers/relayable_json_parser_spec.rb
index bab94ff..f878b49 100644
--- a/spec/lib/diaspora_federation/parsers/relayable_json_parser_spec.rb
+++ b/spec/lib/diaspora_federation/parsers/relayable_json_parser_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Parsers::RelayableJsonParser do
     describe ".parse" do
@@ -8,17 +10,17 @@ module DiasporaFederation
                        '{"entity_type": "some_relayable", "entity_data": {}}'
 
       it "returns property order as a second argument" do
-        json = JSON.parse <<-JSON
-{
-  "entity_type": "some_relayable",
-  "property_order": ["property", "guid", "author"],
-  "entity_data": {
-    "author": "id@example.tld",
-    "guid": "im a guid",
-    "property": "value"
-  }
-}
-JSON
+        json = JSON.parse <<~JSON
+          {
+            "entity_type": "some_relayable",
+            "property_order": ["property", "guid", "author"],
+            "entity_data": {
+              "author": "id@example.tld",
+              "guid": "im a guid",
+              "property": "value"
+            }
+          }
+        JSON
         parsed_data = json_parser.parse(json)
         expect(parsed_data[0]).to be_a(Hash)
         expect(parsed_data[0][:guid]).to eq("im a guid")
diff --git a/spec/lib/diaspora_federation/parsers/relayable_xml_parser_spec.rb b/spec/lib/diaspora_federation/parsers/relayable_xml_parser_spec.rb
index d3f524e..5c465a0 100644
--- a/spec/lib/diaspora_federation/parsers/relayable_xml_parser_spec.rb
+++ b/spec/lib/diaspora_federation/parsers/relayable_xml_parser_spec.rb
@@ -1,16 +1,18 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Parsers::RelayableXmlParser do
     describe ".parse" do
       let(:entity_class) { Entities::SomeRelayable }
       let(:xml_parser) { Parsers::RelayableXmlParser.new(entity_class) }
       it "passes order of the XML elements as a second argument in the returned list" do
-        xml_object = Nokogiri::XML(<<-XML).root
-<some_relayable>
-  <guid>im a guid</guid>
-  <property>value</property>
-  <author>id@example.tld</author>
-</some_relayable>
-XML
+        xml_object = Nokogiri::XML(<<~XML).root
+          <some_relayable>
+            <guid>im a guid</guid>
+            <property>value</property>
+            <author>id@example.tld</author>
+          </some_relayable>
+        XML
 
         parsed_data = xml_parser.parse(xml_object)
         expect(parsed_data[0]).to be_a(Hash)
diff --git a/spec/lib/diaspora_federation/parsers/xml_parser_spec.rb b/spec/lib/diaspora_federation/parsers/xml_parser_spec.rb
index fdcf4b6..da3a661 100644
--- a/spec/lib/diaspora_federation/parsers/xml_parser_spec.rb
+++ b/spec/lib/diaspora_federation/parsers/xml_parser_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Parsers::XmlParser do
     describe ".parse" do
@@ -11,11 +13,11 @@ module DiasporaFederation
       end
 
       it "raises an error when the entity class doesn't match the root node" do
-        xml = <<-XML
-<unknown_entity>
-  <test>asdf</test>
-</unknown_entity>
-XML
+        xml = <<~XML
+          <unknown_entity>
+            <test>asdf</test>
+          </unknown_entity>
+        XML
 
         expect {
           xml_parser.parse(Nokogiri::XML(xml).root)
@@ -32,12 +34,12 @@ XML
       end
 
       it "uses xml_name for parsing" do
-        xml = <<-XML.strip
-<test_entity_with_xml_name>
-  <test>asdf</test>
-  <asdf>qwer</asdf>
-</test_entity_with_xml_name>
-XML
+        xml = <<~XML.strip
+          <test_entity_with_xml_name>
+            <test>asdf</test>
+            <asdf>qwer</asdf>
+          </test_entity_with_xml_name>
+        XML
 
         parsed = Parsers::XmlParser.new(Entities::TestEntityWithXmlName).parse(Nokogiri::XML(xml).root)
 
@@ -46,12 +48,12 @@ XML
       end
 
       it "allows name for parsing even when property has a xml_name" do
-        xml = <<-XML.strip
-<test_entity_with_xml_name>
-  <test>asdf</test>
-  <qwer>qwer</qwer>
-</test_entity_with_xml_name>
-XML
+        xml = <<~XML.strip
+          <test_entity_with_xml_name>
+            <test>asdf</test>
+            <qwer>qwer</qwer>
+          </test_entity_with_xml_name>
+        XML
 
         parsed = Parsers::XmlParser.new(Entities::TestEntityWithXmlName).parse(Nokogiri::XML(xml).root)
 
@@ -60,13 +62,13 @@ XML
       end
 
       it "parses the string to the correct type" do
-        xml = <<-XML.strip
-<test_default_entity>
-  <test1>asdf</test1>
-  <test2>qwer</qwer2>
-  <test3>true</qwer3>
-</test_default_entity>
-XML
+        xml = <<~XML.strip
+          <test_default_entity>
+            <test1>asdf</test1>
+            <test2>qwer</qwer2>
+            <test3>true</qwer3>
+          </test_default_entity>
+        XML
 
         parsed = Parsers::XmlParser.new(Entities::TestDefaultEntity).parse(Nokogiri::XML(xml).root)
 
@@ -76,11 +78,11 @@ XML
       end
 
       it "parses boolean fields with false value" do
-        xml = <<-XML.strip
-<test_entity_with_boolean>
-  <test>false</test>
-</test_entity_with_boolean>
-XML
+        xml = <<~XML.strip
+          <test_entity_with_boolean>
+            <test>false</test>
+          </test_entity_with_boolean>
+        XML
 
         parsed = Parsers::XmlParser.new(Entities::TestEntityWithBoolean).parse(Nokogiri::XML(xml).root)
         expect(parsed[0][:test]).to eq(false)
@@ -88,11 +90,11 @@ XML
 
       it "parses boolean fields with a randomly matching pattern as nil" do
         %w[ttFFFtt yesFFDSFSDy noDFDSFFDFn fXf LLyes].each do |weird_value|
-          xml = <<-XML.strip
-<test_entity_with_boolean>
-  <test>#{weird_value}</test>
-</test_entity_with_boolean>
-XML
+          xml = <<~XML.strip
+            <test_entity_with_boolean>
+              <test>#{weird_value}</test>
+            </test_entity_with_boolean>
+          XML
 
           parsed = Parsers::XmlParser.new(Entities::TestEntityWithBoolean).parse(
             Nokogiri::XML(xml).root
@@ -103,11 +105,11 @@ XML
 
       it "parses integer fields with a randomly matching pattern as nil" do
         %w[1,2,3 foobar two].each do |weird_value|
-          xml = <<-XML.strip
-<test_entity_with_integer>
-  <test>#{weird_value}</test>
-</test_entity_with_integer>
-XML
+          xml = <<~XML.strip
+            <test_entity_with_integer>
+              <test>#{weird_value}</test>
+            </test_entity_with_integer>
+          XML
 
           parsed = Parsers::XmlParser.new(Entities::TestEntityWithInteger).parse(
             Nokogiri::XML(xml).root
@@ -118,11 +120,11 @@ XML
 
       it "parses timestamp fields with a randomly matching pattern as nil" do
         %w[foobar yesterday now 1.2.foo].each do |weird_value|
-          xml = <<-XML.strip
-<test_entity_with_timestamp>
-  <test>#{weird_value}</test>
-</test_entity_with_timestamp>
-XML
+          xml = <<~XML.strip
+            <test_entity_with_timestamp>
+              <test>#{weird_value}</test>
+            </test_entity_with_timestamp>
+          XML
 
           parsed = Parsers::XmlParser.new(Entities::TestEntityWithTimestamp).parse(
             Nokogiri::XML(xml).root
@@ -152,14 +154,14 @@ XML
       end
 
       it "doesn't drop extra properties" do
-        xml = <<-XML.strip
-<test_default_entity>
-  <test1>asdf</test1>
-  <test2>qwer</test2>
-  <test3>true</test3>
-  <test_new>new_value</test_new>
-</test_default_entity>
-XML
+        xml = <<~XML.strip
+          <test_default_entity>
+            <test1>asdf</test1>
+            <test2>qwer</test2>
+            <test3>true</test3>
+            <test_new>new_value</test_new>
+          </test_default_entity>
+        XML
 
         parsed = Parsers::XmlParser.new(Entities::TestDefaultEntity).parse(Nokogiri::XML(xml).root)
         expect(parsed[0]["test_new"]).to eq("new_value")
diff --git a/spec/lib/diaspora_federation/properties_dsl_spec.rb b/spec/lib/diaspora_federation/properties_dsl_spec.rb
index d7ce682..f5ff9ee 100644
--- a/spec/lib/diaspora_federation/properties_dsl_spec.rb
+++ b/spec/lib/diaspora_federation/properties_dsl_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe PropertiesDSL do
     subject(:dsl) { Class.new.extend(PropertiesDSL) }
diff --git a/spec/lib/diaspora_federation/salmon/aes_spec.rb b/spec/lib/diaspora_federation/salmon/aes_spec.rb
index cd0db9e..8fa5af0 100644
--- a/spec/lib/diaspora_federation/salmon/aes_spec.rb
+++ b/spec/lib/diaspora_federation/salmon/aes_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Salmon::AES do
     let(:data) { "test data string" }
diff --git a/spec/lib/diaspora_federation/salmon/encrypted_magic_envelope_spec.rb b/spec/lib/diaspora_federation/salmon/encrypted_magic_envelope_spec.rb
index 7b5f264..de6d97a 100644
--- a/spec/lib/diaspora_federation/salmon/encrypted_magic_envelope_spec.rb
+++ b/spec/lib/diaspora_federation/salmon/encrypted_magic_envelope_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Salmon::EncryptedMagicEnvelope do
     let(:sender_id) { Fabricate.sequence(:diaspora_id) }
diff --git a/spec/lib/diaspora_federation/salmon/encrypted_slap_spec.rb b/spec/lib/diaspora_federation/salmon/encrypted_slap_spec.rb
index 43349f0..348dcfb 100644
--- a/spec/lib/diaspora_federation/salmon/encrypted_slap_spec.rb
+++ b/spec/lib/diaspora_federation/salmon/encrypted_slap_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Salmon::EncryptedSlap do
     let(:sender) { "user_test@diaspora.example.tld" }
@@ -25,21 +27,21 @@ module DiasporaFederation
         end
 
         it "verifies the existence of 'encrypted_header'" do
-          faulty_xml = <<XML
-<diaspora xmlns="https://joindiaspora.com/protocol" xmlns:me="http://salmon-protocol.org/ns/magic-env">
-</diaspora>
-XML
+          faulty_xml = <<~XML
+            <diaspora xmlns="https://joindiaspora.com/protocol" xmlns:me="http://salmon-protocol.org/ns/magic-env">
+            </diaspora>
+          XML
           expect {
             Salmon::EncryptedSlap.from_xml(faulty_xml, recipient_key)
           }.to raise_error Salmon::MissingHeader
         end
 
         it "verifies the existence of a magic envelope" do
-          faulty_xml = <<XML
-<diaspora xmlns="https://joindiaspora.com/protocol" xmlns:me="http://salmon-protocol.org/ns/magic-env">
-  <encrypted_header/>
-</diaspora>
-XML
+          faulty_xml = <<~XML
+            <diaspora xmlns="https://joindiaspora.com/protocol" xmlns:me="http://salmon-protocol.org/ns/magic-env">
+              <encrypted_header/>
+            </diaspora>
+          XML
           expect(Salmon::EncryptedSlap).to receive(:header_data).and_return(aes_key: "", iv: "", author_id: "")
           expect {
             Salmon::EncryptedSlap.from_xml(faulty_xml, recipient_key)
diff --git a/spec/lib/diaspora_federation/salmon/magic_envelope_spec.rb b/spec/lib/diaspora_federation/salmon/magic_envelope_spec.rb
index 01d28e5..b3f1b27 100644
--- a/spec/lib/diaspora_federation/salmon/magic_envelope_spec.rb
+++ b/spec/lib/diaspora_federation/salmon/magic_envelope_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Salmon::MagicEnvelope do
     let(:sender) { Fabricate.sequence(:diaspora_id) }
diff --git a/spec/lib/diaspora_federation/salmon/slap_spec.rb b/spec/lib/diaspora_federation/salmon/slap_spec.rb
index 465f827..a79729d 100644
--- a/spec/lib/diaspora_federation/salmon/slap_spec.rb
+++ b/spec/lib/diaspora_federation/salmon/slap_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Salmon::Slap do
     let(:sender) { "test_user@pod.somedomain.tld" }
@@ -24,24 +26,24 @@ module DiasporaFederation
         end
 
         it "verifies the existence of an author_id" do
-          faulty_xml = <<XML
-<diaspora xmlns="https://joindiaspora.com/protocol" xmlns:me="http://salmon-protocol.org/ns/magic-env">
-  <header/>
-</diaspora>
-XML
+          faulty_xml = <<~XML
+            <diaspora xmlns="https://joindiaspora.com/protocol" xmlns:me="http://salmon-protocol.org/ns/magic-env">
+              <header/>
+            </diaspora>
+          XML
           expect {
             Salmon::Slap.from_xml(faulty_xml)
           }.to raise_error Salmon::MissingAuthor
         end
 
         it "verifies the existence of a magic envelope" do
-          faulty_xml = <<-XML
-<diaspora xmlns="https://joindiaspora.com/protocol" xmlns:me="http://salmon-protocol.org/ns/magic-env">
-  <header>
-    <author_id>#{sender}</author_id>
-  </header>
-</diaspora>
-XML
+          faulty_xml = <<~XML
+            <diaspora xmlns="https://joindiaspora.com/protocol" xmlns:me="http://salmon-protocol.org/ns/magic-env">
+              <header>
+                <author_id>#{sender}</author_id>
+              </header>
+            </diaspora>
+          XML
           expect {
             Salmon::Slap.from_xml(faulty_xml)
           }.to raise_error Salmon::MissingMagicEnvelope
diff --git a/spec/lib/diaspora_federation/salmon/xml_payload_spec.rb b/spec/lib/diaspora_federation/salmon/xml_payload_spec.rb
index c254580..180949b 100644
--- a/spec/lib/diaspora_federation/salmon/xml_payload_spec.rb
+++ b/spec/lib/diaspora_federation/salmon/xml_payload_spec.rb
@@ -1,15 +1,17 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Salmon::XmlPayload do
     let(:entity) { Entities::TestEntity.new(test: "asdf") }
-    let(:entity_xml) { <<-XML.strip }
-<XML>
-  <post>
-    <test_entity>
-      <test>asdf</test>
-    </test_entity>
-  </post>
-</XML>
-XML
+    let(:entity_xml) { <<~XML.strip }
+      <XML>
+        <post>
+          <test_entity>
+            <test>asdf</test>
+          </test_entity>
+        </post>
+      </XML>
+    XML
 
     describe ".unpack" do
       context "sanity" do
@@ -41,11 +43,11 @@ XML
         end
 
         it "allows unwrapped entities" do
-          xml = <<-XML
-<test_entity>
-  <test>asdf</test>
-</test_entity>
-XML
+          xml = <<~XML
+            <test_entity>
+              <test>asdf</test>
+            </test_entity>
+          XML
 
           entity = Salmon::XmlPayload.unpack(Nokogiri::XML(xml).root)
 
diff --git a/spec/lib/diaspora_federation/schemas_spec.rb b/spec/lib/diaspora_federation/schemas_spec.rb
index 4ac5107..f41c1a1 100644
--- a/spec/lib/diaspora_federation/schemas_spec.rb
+++ b/spec/lib/diaspora_federation/schemas_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "diaspora_federation/schemas"
 
 module DiasporaFederation
diff --git a/spec/lib/diaspora_federation/validators/account_deletion_validator_spec.rb b/spec/lib/diaspora_federation/validators/account_deletion_validator_spec.rb
index 2c76af6..78c5463 100644
--- a/spec/lib/diaspora_federation/validators/account_deletion_validator_spec.rb
+++ b/spec/lib/diaspora_federation/validators/account_deletion_validator_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Validators::AccountDeletionValidator do
     let(:entity) { :account_deletion_entity }
diff --git a/spec/lib/diaspora_federation/validators/account_migration_validator_spec.rb b/spec/lib/diaspora_federation/validators/account_migration_validator_spec.rb
index e8c4ea5..77e0f0b 100644
--- a/spec/lib/diaspora_federation/validators/account_migration_validator_spec.rb
+++ b/spec/lib/diaspora_federation/validators/account_migration_validator_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Validators::AccountMigrationValidator do
     let(:entity) { :account_migration_entity }
diff --git a/spec/lib/diaspora_federation/validators/comment_validator_spec.rb b/spec/lib/diaspora_federation/validators/comment_validator_spec.rb
index 5a0b0c5..34c3529 100644
--- a/spec/lib/diaspora_federation/validators/comment_validator_spec.rb
+++ b/spec/lib/diaspora_federation/validators/comment_validator_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Validators::CommentValidator do
     let(:entity) { :comment_entity }
diff --git a/spec/lib/diaspora_federation/validators/contact_validator_spec.rb b/spec/lib/diaspora_federation/validators/contact_validator_spec.rb
index 1e5b926..171415e 100644
--- a/spec/lib/diaspora_federation/validators/contact_validator_spec.rb
+++ b/spec/lib/diaspora_federation/validators/contact_validator_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Validators::ContactValidator do
     let(:entity) { :contact_entity }
diff --git a/spec/lib/diaspora_federation/validators/conversation_validator_spec.rb b/spec/lib/diaspora_federation/validators/conversation_validator_spec.rb
index d5f93a9..4a9f3da 100644
--- a/spec/lib/diaspora_federation/validators/conversation_validator_spec.rb
+++ b/spec/lib/diaspora_federation/validators/conversation_validator_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Validators::ConversationValidator do
     let(:entity) { :conversation_entity }
diff --git a/spec/lib/diaspora_federation/validators/embed_validator_spec.rb b/spec/lib/diaspora_federation/validators/embed_validator_spec.rb
index d6045b3..d9639dc 100644
--- a/spec/lib/diaspora_federation/validators/embed_validator_spec.rb
+++ b/spec/lib/diaspora_federation/validators/embed_validator_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Validators::EmbedValidator do
     let(:entity) { :embed_entity }
diff --git a/spec/lib/diaspora_federation/validators/event_participation_validator_spec.rb b/spec/lib/diaspora_federation/validators/event_participation_validator_spec.rb
index f7e1358..288f6ba 100644
--- a/spec/lib/diaspora_federation/validators/event_participation_validator_spec.rb
+++ b/spec/lib/diaspora_federation/validators/event_participation_validator_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Validators::EventParticipationValidator do
     let(:entity) { :event_participation_entity }
diff --git a/spec/lib/diaspora_federation/validators/event_validator_spec.rb b/spec/lib/diaspora_federation/validators/event_validator_spec.rb
index c516a95..64efe53 100644
--- a/spec/lib/diaspora_federation/validators/event_validator_spec.rb
+++ b/spec/lib/diaspora_federation/validators/event_validator_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Validators::EventValidator do
     let(:entity) { :event_entity }
diff --git a/spec/lib/diaspora_federation/validators/h_card_validator_spec.rb b/spec/lib/diaspora_federation/validators/h_card_validator_spec.rb
index ac70097..30f89dc 100644
--- a/spec/lib/diaspora_federation/validators/h_card_validator_spec.rb
+++ b/spec/lib/diaspora_federation/validators/h_card_validator_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Validators::HCardValidator do
     let(:entity) { :h_card }
diff --git a/spec/lib/diaspora_federation/validators/like_validator_spec.rb b/spec/lib/diaspora_federation/validators/like_validator_spec.rb
index 34888d6..6529245 100644
--- a/spec/lib/diaspora_federation/validators/like_validator_spec.rb
+++ b/spec/lib/diaspora_federation/validators/like_validator_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Validators::LikeValidator do
     let(:entity) { :like_entity }
diff --git a/spec/lib/diaspora_federation/validators/location_validator_spec.rb b/spec/lib/diaspora_federation/validators/location_validator_spec.rb
index 1b60840..ffe81da 100644
--- a/spec/lib/diaspora_federation/validators/location_validator_spec.rb
+++ b/spec/lib/diaspora_federation/validators/location_validator_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Validators::LocationValidator do
     let(:entity) { :location_entity }
diff --git a/spec/lib/diaspora_federation/validators/message_validator_spec.rb b/spec/lib/diaspora_federation/validators/message_validator_spec.rb
index 0889cbb..571fd96 100644
--- a/spec/lib/diaspora_federation/validators/message_validator_spec.rb
+++ b/spec/lib/diaspora_federation/validators/message_validator_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Validators::MessageValidator do
     let(:entity) { :message_entity }
diff --git a/spec/lib/diaspora_federation/validators/optional_aware_validator_spec.rb b/spec/lib/diaspora_federation/validators/optional_aware_validator_spec.rb
index 049ee49..047af2b 100644
--- a/spec/lib/diaspora_federation/validators/optional_aware_validator_spec.rb
+++ b/spec/lib/diaspora_federation/validators/optional_aware_validator_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Validators::OptionalAwareValidator do
     def entity_stub(additional_data={})
diff --git a/spec/lib/diaspora_federation/validators/participation_validator_spec.rb b/spec/lib/diaspora_federation/validators/participation_validator_spec.rb
index 7ffdcfc..7983cea 100644
--- a/spec/lib/diaspora_federation/validators/participation_validator_spec.rb
+++ b/spec/lib/diaspora_federation/validators/participation_validator_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Validators::ParticipationValidator do
     let(:entity) { :participation_entity }
diff --git a/spec/lib/diaspora_federation/validators/person_validator_spec.rb b/spec/lib/diaspora_federation/validators/person_validator_spec.rb
index 6b7d61d..e8c195f 100644
--- a/spec/lib/diaspora_federation/validators/person_validator_spec.rb
+++ b/spec/lib/diaspora_federation/validators/person_validator_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Validators::PersonValidator do
     let(:entity) { :person_entity }
diff --git a/spec/lib/diaspora_federation/validators/photo_validator_spec.rb b/spec/lib/diaspora_federation/validators/photo_validator_spec.rb
index 342ebac..e55cfec 100644
--- a/spec/lib/diaspora_federation/validators/photo_validator_spec.rb
+++ b/spec/lib/diaspora_federation/validators/photo_validator_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Validators::PhotoValidator do
     let(:entity) { :photo_entity }
diff --git a/spec/lib/diaspora_federation/validators/poll_answer_validator_spec.rb b/spec/lib/diaspora_federation/validators/poll_answer_validator_spec.rb
index be1d1e5..f849017 100644
--- a/spec/lib/diaspora_federation/validators/poll_answer_validator_spec.rb
+++ b/spec/lib/diaspora_federation/validators/poll_answer_validator_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Validators::PollAnswerValidator do
     let(:entity) { :poll_answer_entity }
diff --git a/spec/lib/diaspora_federation/validators/poll_participation_validator_spec.rb b/spec/lib/diaspora_federation/validators/poll_participation_validator_spec.rb
index 51215d8..95581ef 100644
--- a/spec/lib/diaspora_federation/validators/poll_participation_validator_spec.rb
+++ b/spec/lib/diaspora_federation/validators/poll_participation_validator_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Validators::PollParticipationValidator do
     let(:entity) { :poll_participation_entity }
diff --git a/spec/lib/diaspora_federation/validators/poll_validator_spec.rb b/spec/lib/diaspora_federation/validators/poll_validator_spec.rb
index 2b26b55..d1fd0b7 100644
--- a/spec/lib/diaspora_federation/validators/poll_validator_spec.rb
+++ b/spec/lib/diaspora_federation/validators/poll_validator_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Validators::PollValidator do
     let(:entity) { :poll_entity }
diff --git a/spec/lib/diaspora_federation/validators/profile_validator_spec.rb b/spec/lib/diaspora_federation/validators/profile_validator_spec.rb
index c9c4e7c..79c5106 100644
--- a/spec/lib/diaspora_federation/validators/profile_validator_spec.rb
+++ b/spec/lib/diaspora_federation/validators/profile_validator_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Validators::ProfileValidator do
     let(:entity) { :profile_entity }
diff --git a/spec/lib/diaspora_federation/validators/related_entity_validator_spec.rb b/spec/lib/diaspora_federation/validators/related_entity_validator_spec.rb
index 56bf669..654b875 100644
--- a/spec/lib/diaspora_federation/validators/related_entity_validator_spec.rb
+++ b/spec/lib/diaspora_federation/validators/related_entity_validator_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Validators::RelatedEntityValidator do
     let(:entity) { :related_entity }
diff --git a/spec/lib/diaspora_federation/validators/reshare_validator_spec.rb b/spec/lib/diaspora_federation/validators/reshare_validator_spec.rb
index 6909ed6..6aaad65 100644
--- a/spec/lib/diaspora_federation/validators/reshare_validator_spec.rb
+++ b/spec/lib/diaspora_federation/validators/reshare_validator_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Validators::ReshareValidator do
     let(:entity) { :reshare_entity }
diff --git a/spec/lib/diaspora_federation/validators/retraction_validator_spec.rb b/spec/lib/diaspora_federation/validators/retraction_validator_spec.rb
index b19294c..917b8d6 100644
--- a/spec/lib/diaspora_federation/validators/retraction_validator_spec.rb
+++ b/spec/lib/diaspora_federation/validators/retraction_validator_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Validators::RetractionValidator do
     let(:entity) { :retraction_entity }
diff --git a/spec/lib/diaspora_federation/validators/rules/birthday_spec.rb b/spec/lib/diaspora_federation/validators/rules/birthday_spec.rb
index 8ed274d..cdee654 100644
--- a/spec/lib/diaspora_federation/validators/rules/birthday_spec.rb
+++ b/spec/lib/diaspora_federation/validators/rules/birthday_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 describe Validation::Rule::Birthday do
   it "will not accept parameters" do
     validator = Validation::Validator.new({})
diff --git a/spec/lib/diaspora_federation/validators/rules/boolean_spec.rb b/spec/lib/diaspora_federation/validators/rules/boolean_spec.rb
index cf95e1b..5151739 100644
--- a/spec/lib/diaspora_federation/validators/rules/boolean_spec.rb
+++ b/spec/lib/diaspora_federation/validators/rules/boolean_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 describe Validation::Rule::Boolean do
   it "will not accept parameters" do
     validator = Validation::Validator.new({})
diff --git a/spec/lib/diaspora_federation/validators/rules/diaspora_id_list_spec.rb b/spec/lib/diaspora_federation/validators/rules/diaspora_id_list_spec.rb
index d6ad026..1030d37 100644
--- a/spec/lib/diaspora_federation/validators/rules/diaspora_id_list_spec.rb
+++ b/spec/lib/diaspora_federation/validators/rules/diaspora_id_list_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 describe Validation::Rule::DiasporaIdList do
   let(:id_str) { Array.new(3) { Fabricate.sequence(:diaspora_id) }.join(";") }
 
diff --git a/spec/lib/diaspora_federation/validators/rules/diaspora_id_spec.rb b/spec/lib/diaspora_federation/validators/rules/diaspora_id_spec.rb
index a796530..d824d9f 100644
--- a/spec/lib/diaspora_federation/validators/rules/diaspora_id_spec.rb
+++ b/spec/lib/diaspora_federation/validators/rules/diaspora_id_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 describe Validation::Rule::DiasporaId do
   it "will not accept parameters" do
     validator = Validation::Validator.new({})
diff --git a/spec/lib/diaspora_federation/validators/rules/guid_spec.rb b/spec/lib/diaspora_federation/validators/rules/guid_spec.rb
index 3a71404..779bc1d 100644
--- a/spec/lib/diaspora_federation/validators/rules/guid_spec.rb
+++ b/spec/lib/diaspora_federation/validators/rules/guid_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 describe Validation::Rule::Guid do
   it "will not accept parameters" do
     validator = Validation::Validator.new({})
diff --git a/spec/lib/diaspora_federation/validators/rules/not_nil_spec.rb b/spec/lib/diaspora_federation/validators/rules/not_nil_spec.rb
index 62709c9..7c10359 100644
--- a/spec/lib/diaspora_federation/validators/rules/not_nil_spec.rb
+++ b/spec/lib/diaspora_federation/validators/rules/not_nil_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 describe Validation::Rule::NotNil do
   it "will not accept parameters" do
     validator = Validation::Validator.new({})
diff --git a/spec/lib/diaspora_federation/validators/rules/public_key_spec.rb b/spec/lib/diaspora_federation/validators/rules/public_key_spec.rb
index ed3b1b6..1691fe6 100644
--- a/spec/lib/diaspora_federation/validators/rules/public_key_spec.rb
+++ b/spec/lib/diaspora_federation/validators/rules/public_key_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 describe Validation::Rule::PublicKey do
   it "will not accept parameters" do
     validator = Validation::Validator.new({})
diff --git a/spec/lib/diaspora_federation/validators/rules/tag_count_spec.rb b/spec/lib/diaspora_federation/validators/rules/tag_count_spec.rb
index 52e8720..b7fb86a 100644
--- a/spec/lib/diaspora_federation/validators/rules/tag_count_spec.rb
+++ b/spec/lib/diaspora_federation/validators/rules/tag_count_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 describe Validation::Rule::TagCount do
   it "requires a parameter" do
     validator = Validation::Validator.new({})
diff --git a/spec/lib/diaspora_federation/validators/status_message_validator_spec.rb b/spec/lib/diaspora_federation/validators/status_message_validator_spec.rb
index 0f8bd4b..26f9bfc 100644
--- a/spec/lib/diaspora_federation/validators/status_message_validator_spec.rb
+++ b/spec/lib/diaspora_federation/validators/status_message_validator_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Validators::StatusMessageValidator do
     let(:entity) { :status_message_entity }
diff --git a/spec/lib/diaspora_federation/validators/web_finger_validator_spec.rb b/spec/lib/diaspora_federation/validators/web_finger_validator_spec.rb
index 8aaf77b..a7aac23 100644
--- a/spec/lib/diaspora_federation/validators/web_finger_validator_spec.rb
+++ b/spec/lib/diaspora_federation/validators/web_finger_validator_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe Validators::WebFingerValidator do
     let(:entity) { :webfinger }
diff --git a/spec/lib/diaspora_federation_spec.rb b/spec/lib/diaspora_federation_spec.rb
index 4451309..e95fe6e 100644
--- a/spec/lib/diaspora_federation_spec.rb
+++ b/spec/lib/diaspora_federation_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe DiasporaFederation do
     context "validate_config" do
diff --git a/spec/routing/fetch_routing_spec.rb b/spec/routing/fetch_routing_spec.rb
index e8c50fe..6dfdb28 100644
--- a/spec/routing/fetch_routing_spec.rb
+++ b/spec/routing/fetch_routing_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe ReceiveController, type: :routing do
     routes { DiasporaFederation::Engine.routes }
diff --git a/spec/routing/receive_routing_spec.rb b/spec/routing/receive_routing_spec.rb
index 87a53b9..a0afc20 100644
--- a/spec/routing/receive_routing_spec.rb
+++ b/spec/routing/receive_routing_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe ReceiveController, type: :routing do
     routes { DiasporaFederation::Engine.routes }
diff --git a/spec/routing/webfinger_routing_spec.rb b/spec/routing/webfinger_routing_spec.rb
index 11f845a..9b1f33b 100644
--- a/spec/routing/webfinger_routing_spec.rb
+++ b/spec/routing/webfinger_routing_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module DiasporaFederation
   describe ReceiveController, type: :routing do
     routes { DiasporaFederation::Engine.routes }
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index b4f4ce2..f20a729 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 unless ENV["NO_COVERAGE"] == "true"
   require "simplecov"
   require "simplecov-rcov"
@@ -52,9 +54,7 @@ RSpec.configure do |config|
     expect_config.syntax = :expect
   end
 
-  if defined?(::Rails)
-    config.filter_run_excluding rails: (::Rails::VERSION::MAJOR == 5 ? 4 : 5)
-  else
+  unless defined?(::Rails)
     config.exclude_pattern = "**/controllers/**/*_spec.rb, **/routing/**/*_spec.rb"
     config.filter_run_excluding rails: true
   end
diff --git a/spec/support/fixture_builder.rb b/spec/support/fixture_builder.rb
index 0e536d5..df473cc 100644
--- a/spec/support/fixture_builder.rb
+++ b/spec/support/fixture_builder.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # set default users as initial database for each test
 RSpec.configure do |config|
   config.before(:suite) do
diff --git a/spec/support/helper_methods.rb b/spec/support/helper_methods.rb
index 12a6f18..b2bb3a6 100644
--- a/spec/support/helper_methods.rb
+++ b/spec/support/helper_methods.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # default users
 def alice
   @alice ||= Person.find_by(diaspora_id: "alice@localhost:3000")
diff --git a/spec/support/legacy_helper.rb b/spec/support/legacy_helper.rb
index 384f43b..d938530 100644
--- a/spec/support/legacy_helper.rb
+++ b/spec/support/legacy_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This file only exists to generate legacy XMLs to test that we can still parse it.
 
 def generate_legacy_salmon_slap(entity, sender, sender_privkey)
diff --git a/spec/support/shared_entity_specs.rb b/spec/support/shared_entity_specs.rb
index a62eaf2..4c7ad42 100644
--- a/spec/support/shared_entity_specs.rb
+++ b/spec/support/shared_entity_specs.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 def entity_hash_from(hash)
   hash.delete(:parent_author_signature)
   hash.map {|key, value|
diff --git a/spec/support/shared_magic_envelope_specs.rb b/spec/support/shared_magic_envelope_specs.rb
index cbfcde3..41ba7fc 100644
--- a/spec/support/shared_magic_envelope_specs.rb
+++ b/spec/support/shared_magic_envelope_specs.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 shared_examples "a MagicEnvelope instance" do
   before do
     allow(DiasporaFederation.callbacks).to receive(:trigger).with(
diff --git a/spec/support/shared_parser_specs.rb b/spec/support/shared_parser_specs.rb
index f5cb26c..96e67f3 100644
--- a/spec/support/shared_parser_specs.rb
+++ b/spec/support/shared_parser_specs.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 shared_examples ".parse parse error" do |reason, json|
   it "raises error when #{reason}" do
     expect {
diff --git a/spec/support/shared_signable_specs.rb b/spec/support/shared_signable_specs.rb
index 8e5140d..3a0619c 100644
--- a/spec/support/shared_signable_specs.rb
+++ b/spec/support/shared_signable_specs.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 shared_examples "a signable" do
   let(:private_key) { OpenSSL::PKey::RSA.generate(1024) }
   let(:test_signature) { sign_with_key(private_key, test_string) }
diff --git a/spec/support/shared_validator_specs.rb b/spec/support/shared_validator_specs.rb
index 862148f..e8d240d 100644
--- a/spec/support/shared_validator_specs.rb
+++ b/spec/support/shared_validator_specs.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 def entity_stub(entity, data={})
   entity_class = Fabricate.schematic(entity).options[:class_name]
   allow_any_instance_of(entity_class).to receive(:freeze)
diff --git a/test/dummy/Rakefile b/test/dummy/Rakefile
index 08cc98f..dbf84da 100644
--- a/test/dummy/Rakefile
+++ b/test/dummy/Rakefile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Add your own tasks in files placed in lib/tasks ending in .rake,
 # for example lib/tasks/capistrano.rake, and they will automatically be available to Rake.
 
diff --git a/test/dummy/app/models/entity.rb b/test/dummy/app/models/entity.rb
index 41135ed..3cbf562 100644
--- a/test/dummy/app/models/entity.rb
+++ b/test/dummy/app/models/entity.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Entity
   attr_accessor :author, :guid
   attr_reader :entity_type
diff --git a/test/dummy/app/models/person.rb b/test/dummy/app/models/person.rb
index cd96c6a..75bb515 100644
--- a/test/dummy/app/models/person.rb
+++ b/test/dummy/app/models/person.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class Person
   attr_accessor :diaspora_id, :url, :guid, :serialized_public_key, :serialized_private_key
 
@@ -34,6 +36,7 @@ class Person
 
     def find_by(opts)
       return database[:diaspora_id][opts[:diaspora_id]] if opts[:diaspora_id]
+
       database[:guid][opts[:guid]]
     end
 
diff --git a/test/dummy/bin/rails b/test/dummy/bin/rails
index 5191e69..0739660 100755
--- a/test/dummy/bin/rails
+++ b/test/dummy/bin/rails
@@ -1,4 +1,4 @@
 #!/usr/bin/env ruby
-APP_PATH = File.expand_path('../../config/application', __FILE__)
+APP_PATH = File.expand_path('../config/application', __dir__)
 require_relative '../config/boot'
 require 'rails/commands'
diff --git a/test/dummy/config.ru b/test/dummy/config.ru
index 193e5fe..097cb7b 100644
--- a/test/dummy/config.ru
+++ b/test/dummy/config.ru
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This file is used by Rack-based servers to start the application.
 
 require ::File.expand_path("../config/environment", __FILE__)
diff --git a/test/dummy/config/application.rb b/test/dummy/config/application.rb
index 7b71468..dccc66d 100644
--- a/test/dummy/config/application.rb
+++ b/test/dummy/config/application.rb
@@ -1,28 +1,35 @@
+# frozen_string_literal: true
+
 require_relative "boot"
 
+require "rails"
+# Pick the frameworks you want:
+# require "active_model/railtie"
+# require "active_job/railtie"
+# require "active_record/railtie"
+# require "active_storage/engine"
 require "action_controller/railtie"
+# require "action_mailer/railtie"
+# require "action_mailbox/engine"
+# require "action_text/engine"
+require "action_view/railtie"
+# require "action_cable/engine"
+# require "sprockets/railtie"
+require "rails/test_unit/railtie"
 
+# Require the gems listed in Gemfile, including any gems
+# you've limited to :test, :development, or :production.
 Bundler.require(*Rails.groups)
 require "diaspora_federation/rails"
 
 module Dummy
   class Application < Rails::Application
+    # Initialize configuration defaults for originally generated Rails version.
+    config.load_defaults 5.0
+
     # Settings in config/environments/* take precedence over those specified here.
-    # Application configuration should go into files in config/initializers
-    # -- all .rb files in that directory are automatically loaded.
-
-    # Set Time.zone default to the specified zone and make Active Record auto-convert to this zone.
-    # Run "rake -D time" for a list of tasks for finding time zone names. Default is UTC.
-    # config.time_zone = 'Central Time (US & Canada)'
-
-    # The default locale is :en and all translations from config/locales/*.rb,yml are auto loaded.
-    # config.i18n.load_path += Dir[Rails.root.join('my', 'locales', '*.{rb,yml}').to_s]
-    # config.i18n.default_locale = :de
-
-    # Version of your assets, change this if you want to expire all your assets
-    # config.assets.version = "1.0"
-
-    # autoload files from test/dummy/lib
-    config.autoload_once_paths += %W[#{config.root}/lib]
+    # Application configuration can go into files in config/initializers
+    # -- all .rb files in that directory are automatically loaded after loading
+    # the framework and any gems in your application.
   end
 end
diff --git a/test/dummy/config/boot.rb b/test/dummy/config/boot.rb
index bb5714c..55bd95c 100644
--- a/test/dummy/config/boot.rb
+++ b/test/dummy/config/boot.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Set up gems listed in the Gemfile.
 ENV["BUNDLE_GEMFILE"] ||= File.expand_path("../../../Gemfile", __dir__)
 require "bundler/setup" if File.exist?(ENV["BUNDLE_GEMFILE"])
diff --git a/test/dummy/config/environment.rb b/test/dummy/config/environment.rb
index f970ac2..7df99e8 100644
--- a/test/dummy/config/environment.rb
+++ b/test/dummy/config/environment.rb
@@ -1,5 +1,7 @@
-# Load the rails application
+# frozen_string_literal: true
+
+# Load the Rails application.
 require_relative "application"
 
-# Initialize the rails application
+# Initialize the Rails application.
 Rails.application.initialize!
diff --git a/test/dummy/config/environments/development.rb b/test/dummy/config/environments/development.rb
index 2d78bb2..d1a500a 100644
--- a/test/dummy/config/environments/development.rb
+++ b/test/dummy/config/environments/development.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 Rails.application.configure do
   # Settings specified here will take precedence over those in config/application.rb.
 
@@ -9,36 +11,35 @@ Rails.application.configure do
   # Do not eager load code on boot.
   config.eager_load = false
 
-  # Show full error reports and disable caching.
-  config.consider_all_requests_local       = true
-  config.action_controller.perform_caching = false
+  # Show full error reports.
+  config.consider_all_requests_local = true
 
-  # Don't care if the mailer can't send.
-  # config.action_mailer.raise_delivery_errors = false
+  # Enable/disable caching. By default caching is disabled.
+  # Run rails dev:cache to toggle caching.
+  if Rails.root.join("tmp", "caching-dev.txt").exist?
+    config.action_controller.perform_caching = true
+    config.action_controller.enable_fragment_cache_logging = true
+
+    config.cache_store = :memory_store
+    config.public_file_server.headers = {
+      "Cache-Control" => "public, max-age=#{2.days.to_i}"
+    }
+  else
+    config.action_controller.perform_caching = false
+
+    config.cache_store = :null_store
+  end
 
   # Print deprecation notices to the Rails logger.
   config.active_support.deprecation = :log
 
-  # Raise an error on page load if there are pending migrations.
-  # config.active_record.migration_error = :page_load
-
-  # Debug mode disables concatenation and preprocessing of assets.
-  # This option may cause significant delays in view rendering with a large
-  # number of complex assets.
-  # config.assets.debug = true
-
-  # Asset digests allow you to set far-future HTTP expiration dates on all assets,
-  # yet still be able to expire them through the digest params.
-  # config.assets.digest = true
-
-  # Adds additional error checking when serving assets at runtime.
-  # Checks for improperly declared sprockets dependencies.
-  # Raises helpful error messages.
-  # config.assets.raise_runtime_errors = true
-
-  # Raises error for missing translations
+  # Raises error for missing translations.
   # config.action_view.raise_on_missing_translations = true
 
+  # Use an evented file watcher to asynchronously detect changes in source code,
+  # routes, locales, etc. This feature depends on the listen gem.
+  config.file_watcher = ActiveSupport::EventedFileUpdateChecker
+
   # Set the logging destination(s)
   config.log_to = %w[stdout file]
 
diff --git a/test/dummy/config/environments/production.rb b/test/dummy/config/environments/production.rb
index da40eee..f7d9dab 100644
--- a/test/dummy/config/environments/production.rb
+++ b/test/dummy/config/environments/production.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 Rails.application.configure do
   # Settings specified here will take precedence over those in config/application.rb.
 
@@ -14,28 +16,16 @@ Rails.application.configure do
   config.consider_all_requests_local       = false
   config.action_controller.perform_caching = true
 
-  # Enable Rack::Cache to put a simple HTTP cache in front of your application
-  # Add `rack-cache` to your Gemfile before enabling this.
-  # For large-scale production use, consider using a caching reverse proxy like
-  # NGINX, varnish or squid.
-  # config.action_dispatch.rack_cache = true
+  # Ensures that a master key has been made available in either ENV["RAILS_MASTER_KEY"]
+  # or in config/master.key. This key is used to decrypt credentials (and other encrypted files).
+  # config.require_master_key = true
 
   # Disable serving static files from the `/public` folder by default since
   # Apache or NGINX already handles this.
-  config.serve_static_files = false
+  config.public_file_server.enabled = ENV["RAILS_SERVE_STATIC_FILES"].present?
 
-  # Compress JavaScripts and CSS.
-  # config.assets.js_compressor = :uglifier
-  # config.assets.css_compressor = :sass
-
-  # Do not fallback to assets pipeline if a precompiled asset is missed.
-  # config.assets.compile = false
-
-  # Asset digests allow you to set far-future HTTP expiration dates on all assets,
-  # yet still be able to expire them through the digest params.
-  # config.assets.digest = true
-
-  # `config.assets.precompile` and `config.assets.version` have moved to config/initializers/assets.rb
+  # Enable serving of images, stylesheets, and JavaScripts from an asset server.
+  # config.action_controller.asset_host = 'http://assets.example.com'
 
   # Specifies the header that your server uses for sending files.
   # config.action_dispatch.x_sendfile_header = 'X-Sendfile' # for Apache
@@ -55,20 +45,14 @@ Rails.application.configure do
   config.show_log_configuration = false
 
   # Prepend all log lines with the following tags.
-  # config.log_tags = [ :subdomain, :uuid ]
-
-  # Use a different logger for distributed setups.
-  # config.logger = ActiveSupport::TaggedLogging.new(SyslogLogger.new)
+  config.log_tags = [:request_id]
 
   # Use a different cache store in production.
   # config.cache_store = :mem_cache_store
 
-  # Enable serving of images, stylesheets, and JavaScripts from an asset server.
-  # config.action_controller.asset_host = 'http://assets.example.com'
-
-  # Ignore bad email addresses and do not raise email delivery errors.
-  # Set this to true and configure the email server for immediate delivery to raise delivery errors.
-  # config.action_mailer.raise_delivery_errors = false
+  # Use a real queuing backend for Active Job (and separate queues per environment).
+  # config.active_job.queue_adapter     = :resque
+  # config.active_job.queue_name_prefix = "dummy_production"
 
   # Enable locale fallbacks for I18n (makes lookups for any locale fall back to
   # the I18n.default_locale when a translation cannot be found).
@@ -80,6 +64,34 @@ Rails.application.configure do
   # Use default logging formatter so that PID and timestamp are not suppressed.
   config.log_formatter = ::Logger::Formatter.new
 
-  # Do not dump schema after migrations.
-  # config.active_record.dump_schema_after_migration = false
+  # Use a different logger for distributed setups.
+  # require 'syslog/logger'
+  # config.logger = ActiveSupport::TaggedLogging.new(Syslog::Logger.new 'app-name')
+
+  if ENV["RAILS_LOG_TO_STDOUT"].present?
+    logger           = ActiveSupport::Logger.new(STDOUT)
+    logger.formatter = config.log_formatter
+    config.logger    = ActiveSupport::TaggedLogging.new(logger)
+  end
+
+  # Inserts middleware to perform automatic connection switching.
+  # The `database_selector` hash is used to pass options to the DatabaseSelector
+  # middleware. The `delay` is used to determine how long to wait after a write
+  # to send a subsequent read to the primary.
+  #
+  # The `database_resolver` class is used by the middleware to determine which
+  # database is appropriate to use based on the time delay.
+  #
+  # The `database_resolver_context` class is used by the middleware to set
+  # timestamps for the last write to the primary. The resolver uses the context
+  # class timestamps to determine how long to wait before reading from the
+  # replica.
+  #
+  # By default Rails will store a last write timestamp in the session. The
+  # DatabaseSelector middleware is designed as such you can define your own
+  # strategy for connection switching and pass that into the middleware through
+  # these configuration options.
+  # config.active_record.database_selector = { delay: 2.seconds }
+  # config.active_record.database_resolver = ActiveRecord::Middleware::DatabaseSelector::Resolver
+  # config.active_record.database_resolver_context = ActiveRecord::Middleware::DatabaseSelector::Resolver::Session
 end
diff --git a/test/dummy/config/environments/test.rb b/test/dummy/config/environments/test.rb
index e7fbf43..bae3b39 100644
--- a/test/dummy/config/environments/test.rb
+++ b/test/dummy/config/environments/test.rb
@@ -1,29 +1,30 @@
+# frozen_string_literal: true
+
+# The test environment is used exclusively to run your application's
+# test suite. You never need to work with it otherwise. Remember that
+# your test database is "scratch space" for the test suite and is wiped
+# and recreated between test runs. Don't rely on the data there!
+
 Rails.application.configure do
   # Settings specified here will take precedence over those in config/application.rb.
 
-  # The test environment is used exclusively to run your application's
-  # test suite. You never need to work with it otherwise. Remember that
-  # your test database is "scratch space" for the test suite and is wiped
-  # and recreated between test runs. Don't rely on the data there!
-  config.cache_classes = true
+  config.cache_classes = false
 
   # Do not eager load code on boot. This avoids loading your whole application
   # just for the purpose of running a single test. If you are using a tool that
   # preloads Rails for running tests, you may have to set it to true.
   config.eager_load = false
 
-  # Configure static file server for tests with Cache-Control for performance.
-  if Rails::VERSION::MAJOR == 5
-    config.public_file_server.enable  = true
-    config.public_file_server.headers = {"Cache-Control" => "public, max-age=3600"}
-  else
-    config.serve_static_files   = true
-    config.static_cache_control = "public, max-age=3600"
-  end
+  # Configure public file server for tests with Cache-Control for performance.
+  config.public_file_server.enabled = true
+  config.public_file_server.headers = {
+    "Cache-Control" => "public, max-age=#{1.hour.to_i}"
+  }
 
   # Show full error reports and disable caching.
   config.consider_all_requests_local       = true
   config.action_controller.perform_caching = false
+  config.cache_store = :null_store
 
   # Raise exceptions instead of rendering exception templates.
   config.action_dispatch.show_exceptions = false
@@ -31,17 +32,9 @@ Rails.application.configure do
   # Disable request forgery protection in test environment.
   config.action_controller.allow_forgery_protection = false
 
-  # Tell Action Mailer not to deliver emails to the real world.
-  # The :test delivery method accumulates sent emails in the
-  # ActionMailer::Base.deliveries array.
-  # config.action_mailer.delivery_method = :test
-
-  # Randomize the order test cases are executed.
-  # config.active_support.test_order = :random
-
   # Print deprecation notices to the stderr.
-  # config.active_support.deprecation = :stderr
+  config.active_support.deprecation = :stderr
 
-  # Raises error for missing translations
+  # Raises error for missing translations.
   # config.action_view.raise_on_missing_translations = true
 end
diff --git a/test/dummy/config/initializers/cookies_serializer.rb b/test/dummy/config/initializers/cookies_serializer.rb
new file mode 100644
index 0000000..20a704a
--- /dev/null
+++ b/test/dummy/config/initializers/cookies_serializer.rb
@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+# Be sure to restart your server when you modify this file.
+
+# Specify a serializer for the signed and encrypted cookie jars.
+# Valid options are :json, :marshal, and :hybrid.
+Rails.application.config.action_dispatch.cookies_serializer = :marshal
diff --git a/test/dummy/config/initializers/diaspora_federation.rb b/test/dummy/config/initializers/diaspora_federation.rb
index 430b5e8..09eed96 100644
--- a/test/dummy/config/initializers/diaspora_federation.rb
+++ b/test/dummy/config/initializers/diaspora_federation.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "diaspora_federation"
 
 ca_file = if File.file?("/etc/ssl/certs/ca-certificates.crt")
diff --git a/test/dummy/config/initializers/faraday.rb b/test/dummy/config/initializers/faraday.rb
index 027a3fa..856578c 100644
--- a/test/dummy/config/initializers/faraday.rb
+++ b/test/dummy/config/initializers/faraday.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Use net_http in test, that's better supported by webmock
 unless Rails.env.test?
   require "typhoeus/adapters/faraday"
diff --git a/test/dummy/config/initializers/filter_parameter_logging.rb b/test/dummy/config/initializers/filter_parameter_logging.rb
index 4a994e1..7a4f47b 100644
--- a/test/dummy/config/initializers/filter_parameter_logging.rb
+++ b/test/dummy/config/initializers/filter_parameter_logging.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Be sure to restart your server when you modify this file.
 
 # Configure sensitive parameters which will be filtered from the log file.
diff --git a/test/dummy/config/initializers/session_store.rb b/test/dummy/config/initializers/session_store.rb
index 7ee20e3..606745f 100644
--- a/test/dummy/config/initializers/session_store.rb
+++ b/test/dummy/config/initializers/session_store.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Be sure to restart your server when you modify this file.
 
 Rails.application.config.session_store :cookie_store, key: "_dummy_session"
diff --git a/test/dummy/config/initializers/wrap_parameters.rb b/test/dummy/config/initializers/wrap_parameters.rb
index a7b1b91..e7148a3 100644
--- a/test/dummy/config/initializers/wrap_parameters.rb
+++ b/test/dummy/config/initializers/wrap_parameters.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Be sure to restart your server when you modify this file.
 
 # This file contains settings for ActionController::ParamsWrapper which
@@ -5,10 +7,5 @@
 
 # Enable parameter wrapping for JSON. You can disable this by setting :format to an empty array.
 ActiveSupport.on_load(:action_controller) do
-  wrap_parameters format: [:json] if respond_to?(:wrap_parameters)
-end
-
-# To enable root element in JSON for ActiveRecord objects.
-ActiveSupport.on_load(:active_record) do
-  self.include_root_in_json = true
+  wrap_parameters format: [:json]
 end
diff --git a/test/dummy/config/routes.rb b/test/dummy/config/routes.rb
index 4dccc36..cabecec 100644
--- a/test/dummy/config/routes.rb
+++ b/test/dummy/config/routes.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 Rails.application.routes.draw do
   mount DiasporaFederation::Engine => "/"
 
diff --git a/test/gemfiles/no-rails.Gemfile b/test/gemfiles/no-rails.Gemfile
index 564f1c4..cd31967 100644
--- a/test/gemfiles/no-rails.Gemfile
+++ b/test/gemfiles/no-rails.Gemfile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 source "https://rubygems.org"
 
 # Declare your gem's dependencies in diaspora_federation.gemspec.
@@ -17,16 +19,16 @@ end
 
 group :test do
   # rspec formatter
-  gem "fuubar", "2.3.2",    require: false
+  gem "fuubar", "2.4.1",    require: false
   gem "nyan-cat-formatter", require: false
 
   # test coverage
-  gem "simplecov",                 "0.16.1",   require: false
+  gem "simplecov",                 "0.17.1",   require: false
   gem "simplecov-rcov",            "0.2.3",    require: false
 
   # test helpers
   gem "json-schema-rspec", "0.0.4"
-  gem "rspec-collection_matchers", "~> 1.1.2"
+  gem "rspec-collection_matchers", "~> 1.2.0"
   gem "rspec-json_expectations",   "~> 2.1"
   gem "webmock",                   "~> 3.0"
 end
@@ -35,7 +37,5 @@ group :development, :test do
   gem "rake"
 
   # unit tests
-  gem "rspec", "~> 3.8.0"
+  gem "rspec", "~> 3.9.0"
 end
-
- gem "fabrication", "< 2.17.0"
diff --git a/test/gemfiles/no-rails.Gemfile.lock b/test/gemfiles/no-rails.Gemfile.lock
index 79926f1..3666cdf 100644
--- a/test/gemfiles/no-rails.Gemfile.lock
+++ b/test/gemfiles/no-rails.Gemfile.lock
@@ -2,7 +2,7 @@ PATH
   remote: ../..
   specs:
     diaspora_federation (0.2.6)
-      faraday (>= 0.9.0, < 0.16.0)
+      faraday (>= 0.9.0, < 0.18.0)
       faraday_middleware (>= 0.10.0, < 0.14.0)
       nokogiri (~> 1.6, >= 1.6.8)
       typhoeus (~> 1.0)
@@ -16,59 +16,59 @@ PATH
 GEM
   remote: https://rubygems.org/
   specs:
-    addressable (2.6.0)
-      public_suffix (>= 2.0.2, < 4.0)
+    addressable (2.7.0)
+      public_suffix (>= 2.0.2, < 5.0)
     crack (0.4.3)
       safe_yaml (~> 1.0.0)
     diff-lcs (1.3)
-    docile (1.3.1)
+    docile (1.3.2)
     ethon (0.12.0)
       ffi (>= 1.3.0)
-    fabrication (2.16.3)
-    faraday (0.15.4)
+    fabrication (2.20.2)
+    faraday (0.17.0)
       multipart-post (>= 1.2, < 3)
     faraday_middleware (0.13.1)
       faraday (>= 0.7.4, < 1.0)
-    ffi (1.10.0)
-    fuubar (2.3.2)
+    ffi (1.11.1)
+    fuubar (2.4.1)
       rspec-core (~> 3.0)
       ruby-progressbar (~> 1.4)
-    hashdiff (0.3.8)
+    hashdiff (1.0.0)
     json (2.2.0)
     json-schema (2.8.1)
       addressable (>= 2.4)
     json-schema-rspec (0.0.4)
       json-schema (~> 2.5)
       rspec
-    macaddr (1.7.1)
-      systemu (~> 2.6.2)
+    macaddr (1.7.2)
+      systemu (~> 2.6.5)
     mini_portile2 (2.4.0)
-    multipart-post (2.0.0)
-    nokogiri (1.9.1)
+    multipart-post (2.1.1)
+    nokogiri (1.10.4)
       mini_portile2 (~> 2.4.0)
     nyan-cat-formatter (0.12.0)
       rspec (>= 2.99, >= 2.14.2, < 4)
-    public_suffix (3.0.3)
-    rake (12.3.2)
-    rspec (3.8.0)
-      rspec-core (~> 3.8.0)
-      rspec-expectations (~> 3.8.0)
-      rspec-mocks (~> 3.8.0)
-    rspec-collection_matchers (1.1.3)
+    public_suffix (4.0.1)
+    rake (13.0.0)
+    rspec (3.9.0)
+      rspec-core (~> 3.9.0)
+      rspec-expectations (~> 3.9.0)
+      rspec-mocks (~> 3.9.0)
+    rspec-collection_matchers (1.2.0)
       rspec-expectations (>= 2.99.0.beta1)
-    rspec-core (3.8.0)
-      rspec-support (~> 3.8.0)
-    rspec-expectations (3.8.2)
+    rspec-core (3.9.0)
+      rspec-support (~> 3.9.0)
+    rspec-expectations (3.9.0)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.8.0)
-    rspec-json_expectations (2.1.0)
-    rspec-mocks (3.8.0)
+      rspec-support (~> 3.9.0)
+    rspec-json_expectations (2.2.0)
+    rspec-mocks (3.9.0)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.8.0)
-    rspec-support (3.8.0)
-    ruby-progressbar (1.10.0)
+      rspec-support (~> 3.9.0)
+    rspec-support (3.9.0)
+    ruby-progressbar (1.10.1)
     safe_yaml (1.0.5)
-    simplecov (0.16.1)
+    simplecov (0.17.1)
       docile (~> 1.1)
       json (>= 1.8, < 3)
       simplecov-html (~> 0.10.0)
@@ -81,10 +81,10 @@ GEM
     uuid (2.3.9)
       macaddr (~> 1.0)
     valid (1.2.0)
-    webmock (3.5.1)
+    webmock (3.7.6)
       addressable (>= 2.3.6)
       crack (>= 0.3.2)
-      hashdiff
+      hashdiff (>= 0.4.0, < 2.0.0)
 
 PLATFORMS
   ruby
@@ -93,17 +93,16 @@ DEPENDENCIES
   diaspora_federation!
   diaspora_federation-json_schema!
   diaspora_federation-test!
-  fabrication (< 2.17.0)
-  fuubar (= 2.3.2)
+  fuubar (= 2.4.1)
   json-schema-rspec (= 0.0.4)
   nyan-cat-formatter
   rake
-  rspec (~> 3.8.0)
-  rspec-collection_matchers (~> 1.1.2)
+  rspec (~> 3.9.0)
+  rspec-collection_matchers (~> 1.2.0)
   rspec-json_expectations (~> 2.1)
-  simplecov (= 0.16.1)
+  simplecov (= 0.17.1)
   simplecov-rcov (= 0.2.3)
   webmock (~> 3.0)
 
 BUNDLED WITH
-   1.17.3
+   2.0.2
diff --git a/test/gemfiles/rails4.Gemfile b/test/gemfiles/rails4.Gemfile
deleted file mode 100644
index 8de5931..0000000
--- a/test/gemfiles/rails4.Gemfile
+++ /dev/null
@@ -1,44 +0,0 @@
-source "https://rubygems.org"
-
-# Declare your gem's dependencies in diaspora_federation.gemspec.
-# Bundler will treat runtime dependencies like base dependencies, and
-# development dependencies will be added by default to the :development group.
-gemspec name: "diaspora_federation", path: "../../"
-
-Dir["diaspora_federation-*.gemspec"].each do |gemspec|
-  plugin = gemspec.scan(/diaspora_federation-(.*)\.gemspec/).flatten.first
-  gemspec(name: "diaspora_federation-#{plugin}", development_group: plugin, path: "../../")
-end
-
-# Declare any dependencies that are still in development here instead of in
-# your gemspec. These might include edge Rails or gems from your path or
-# Git. Remember to move these dependencies to your gemspec before releasing
-# your gem to rubygems.org.
-
-group :test do
-  # rspec formatter
-  gem "fuubar", "2.3.2",    require: false
-  gem "nyan-cat-formatter", require: false
-
-  # test coverage
-  gem "simplecov",                 "0.16.1",   require: false
-  gem "simplecov-rcov",            "0.2.3",    require: false
-
-  # test helpers
-  gem "json-schema-rspec", "0.0.4"
-  gem "rspec-collection_matchers", "~> 1.1.2"
-  gem "rspec-json_expectations",   "~> 2.1"
-  gem "webmock",                   "~> 3.0"
-end
-
-group :development, :test do
-  gem "rake"
-
-  # unit tests
-  gem "rspec", "~> 3.8.0"
-  gem "rspec-rails", "~> 3.8.0"
-end
-
- gem "fabrication", "< 2.17.0"
-
-gem "actionpack", "4.2.8"
diff --git a/test/gemfiles/rails4.Gemfile.lock b/test/gemfiles/rails4.Gemfile.lock
deleted file mode 100644
index 917f535..0000000
--- a/test/gemfiles/rails4.Gemfile.lock
+++ /dev/null
@@ -1,171 +0,0 @@
-PATH
-  remote: ../..
-  specs:
-    diaspora_federation (0.2.6)
-      faraday (>= 0.9.0, < 0.16.0)
-      faraday_middleware (>= 0.10.0, < 0.14.0)
-      nokogiri (~> 1.6, >= 1.6.8)
-      typhoeus (~> 1.0)
-      valid (~> 1.0)
-    diaspora_federation-json_schema (0.2.6)
-    diaspora_federation-rails (0.2.6)
-      actionpack (>= 4.2, < 6)
-      diaspora_federation (= 0.2.6)
-    diaspora_federation-test (0.2.6)
-      diaspora_federation (= 0.2.6)
-      fabrication (~> 2.16)
-      uuid (~> 2.3, >= 2.3.8)
-
-GEM
-  remote: https://rubygems.org/
-  specs:
-    actionpack (4.2.8)
-      actionview (= 4.2.8)
-      activesupport (= 4.2.8)
-      rack (~> 1.6)
-      rack-test (~> 0.6.2)
-      rails-dom-testing (~> 1.0, >= 1.0.5)
-      rails-html-sanitizer (~> 1.0, >= 1.0.2)
-    actionview (4.2.8)
-      activesupport (= 4.2.8)
-      builder (~> 3.1)
-      erubis (~> 2.7.0)
-      rails-dom-testing (~> 1.0, >= 1.0.5)
-      rails-html-sanitizer (~> 1.0, >= 1.0.3)
-    activesupport (4.2.8)
-      i18n (~> 0.7)
-      minitest (~> 5.1)
-      thread_safe (~> 0.3, >= 0.3.4)
-      tzinfo (~> 1.1)
-    addressable (2.6.0)
-      public_suffix (>= 2.0.2, < 4.0)
-    builder (3.2.3)
-    concurrent-ruby (1.1.5)
-    crack (0.4.3)
-      safe_yaml (~> 1.0.0)
-    crass (1.0.4)
-    diff-lcs (1.3)
-    docile (1.3.1)
-    erubis (2.7.0)
-    ethon (0.12.0)
-      ffi (>= 1.3.0)
-    fabrication (2.16.3)
-    faraday (0.15.4)
-      multipart-post (>= 1.2, < 3)
-    faraday_middleware (0.13.1)
-      faraday (>= 0.7.4, < 1.0)
-    ffi (1.10.0)
-    fuubar (2.3.2)
-      rspec-core (~> 3.0)
-      ruby-progressbar (~> 1.4)
-    hashdiff (0.3.8)
-    i18n (0.9.5)
-      concurrent-ruby (~> 1.0)
-    json (2.2.0)
-    json-schema (2.8.1)
-      addressable (>= 2.4)
-    json-schema-rspec (0.0.4)
-      json-schema (~> 2.5)
-      rspec
-    loofah (2.2.3)
-      crass (~> 1.0.2)
-      nokogiri (>= 1.5.9)
-    macaddr (1.7.1)
-      systemu (~> 2.6.2)
-    mini_portile2 (2.4.0)
-    minitest (5.11.3)
-    multipart-post (2.0.0)
-    nokogiri (1.9.1)
-      mini_portile2 (~> 2.4.0)
-    nyan-cat-formatter (0.12.0)
-      rspec (>= 2.99, >= 2.14.2, < 4)
-    public_suffix (3.0.3)
-    rack (1.6.11)
-    rack-test (0.6.3)
-      rack (>= 1.0)
-    rails-deprecated_sanitizer (1.0.3)
-      activesupport (>= 4.2.0.alpha)
-    rails-dom-testing (1.0.9)
-      activesupport (>= 4.2.0, < 5.0)
-      nokogiri (~> 1.6)
-      rails-deprecated_sanitizer (>= 1.0.1)
-    rails-html-sanitizer (1.0.4)
-      loofah (~> 2.2, >= 2.2.2)
-    railties (4.2.8)
-      actionpack (= 4.2.8)
-      activesupport (= 4.2.8)
-      rake (>= 0.8.7)
-      thor (>= 0.18.1, < 2.0)
-    rake (12.3.2)
-    rspec (3.8.0)
-      rspec-core (~> 3.8.0)
-      rspec-expectations (~> 3.8.0)
-      rspec-mocks (~> 3.8.0)
-    rspec-collection_matchers (1.1.3)
-      rspec-expectations (>= 2.99.0.beta1)
-    rspec-core (3.8.0)
-      rspec-support (~> 3.8.0)
-    rspec-expectations (3.8.2)
-      diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.8.0)
-    rspec-json_expectations (2.1.0)
-    rspec-mocks (3.8.0)
-      diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.8.0)
-    rspec-rails (3.8.2)
-      actionpack (>= 3.0)
-      activesupport (>= 3.0)
-      railties (>= 3.0)
-      rspec-core (~> 3.8.0)
-      rspec-expectations (~> 3.8.0)
-      rspec-mocks (~> 3.8.0)
-      rspec-support (~> 3.8.0)
-    rspec-support (3.8.0)
-    ruby-progressbar (1.10.0)
-    safe_yaml (1.0.5)
-    simplecov (0.16.1)
-      docile (~> 1.1)
-      json (>= 1.8, < 3)
-      simplecov-html (~> 0.10.0)
-    simplecov-html (0.10.2)
-    simplecov-rcov (0.2.3)
-      simplecov (>= 0.4.1)
-    systemu (2.6.5)
-    thor (0.20.3)
-    thread_safe (0.3.6)
-    typhoeus (1.3.1)
-      ethon (>= 0.9.0)
-    tzinfo (1.2.5)
-      thread_safe (~> 0.1)
-    uuid (2.3.9)
-      macaddr (~> 1.0)
-    valid (1.2.0)
-    webmock (3.5.1)
-      addressable (>= 2.3.6)
-      crack (>= 0.3.2)
-      hashdiff
-
-PLATFORMS
-  ruby
-
-DEPENDENCIES
-  actionpack (= 4.2.8)
-  diaspora_federation!
-  diaspora_federation-json_schema!
-  diaspora_federation-rails!
-  diaspora_federation-test!
-  fabrication (< 2.17.0)
-  fuubar (= 2.3.2)
-  json-schema-rspec (= 0.0.4)
-  nyan-cat-formatter
-  rake
-  rspec (~> 3.8.0)
-  rspec-collection_matchers (~> 1.1.2)
-  rspec-json_expectations (~> 2.1)
-  rspec-rails (~> 3.8.0)
-  simplecov (= 0.16.1)
-  simplecov-rcov (= 0.2.3)
-  webmock (~> 3.0)
-
-BUNDLED WITH
-   1.17.3