Backport new mention syntax to old syntax for backward compatibility

See #7276

lib/diaspora/mentionable.rb

@@ -29,8 +29,8 @@ module Diaspora::Mentionable
     people = [*people]
 
     msg_text.to_s.gsub(REGEX) {|match_str|
-      name, handle = mention_attrs(match_str)
-      person = people.find {|p| p.diaspora_handle == handle }
+      name, diaspora_id = mention_attrs(match_str)
+      person = people.find {|p| p.diaspora_handle == diaspora_id }
 
       ERB::Util.h(MentionsInternal.mention_link(person, name, opts))
     }
@@ -42,10 +42,7 @@ module Diaspora::Mentionable
   # @param [String] text containing mentions
   # @return [Array<Person>] array of people
   def self.people_from_string(msg_text)
-    identifiers = msg_text.to_s.scan(REGEX).map do |match_str|
-      identifier = match_str.second.strip
-      identifier if Validation::Rule::DiasporaId.new.valid_value?(identifier)
-    end
+    identifiers = msg_text.to_s.scan(REGEX).map {|match_str| match_str.second.strip }
 
     identifiers.compact.uniq.map {|identifier| find_or_fetch_person_by_identifier(identifier) }.compact
   end
@@ -61,16 +58,30 @@ module Diaspora::Mentionable
     mentioned_ppl = people_from_string(msg_text)
 
     msg_text.to_s.gsub(REGEX) {|match_str|
-      name, handle = mention_attrs(match_str)
-      person = mentioned_ppl.find {|p| p.diaspora_handle == handle }
+      name, diaspora_id = mention_attrs(match_str)
+      person = mentioned_ppl.find {|p| p.diaspora_handle == diaspora_id }
       mention = MentionsInternal.profile_link(person, name) unless allowed_people.include?(person.id)
 
       mention || match_str
     }
   end
 
+  # Regex to find mentions with new syntax, only used for backporting to old syntax
+  NEW_SYNTAX_REGEX = /@\{[^ ]+\}/
+
+  # replaces new syntax with old syntax, to be compatible with old pods
+  # @deprecated remove when most of the posts can handle the new syntax
+  def self.backport_mention_syntax(text)
+    text.to_s.gsub(NEW_SYNTAX_REGEX) do |match_str|
+      _, diaspora_id = mention_attrs(match_str)
+      person = find_or_fetch_person_by_identifier(diaspora_id)
+      old_syntax = "@{#{person.name}; #{diaspora_id}}" if person
+      old_syntax || match_str
+    end
+  end
+
   private_class_method def self.find_or_fetch_person_by_identifier(identifier)
-    Person.find_or_fetch_by_identifier(identifier)
+    Person.find_or_fetch_by_identifier(identifier) if Validation::Rule::DiasporaId.new.valid_value?(identifier)
   rescue DiasporaFederation::Discovery::DiscoveryError
     nil
   end

lib/diaspora/mentions_container.rb

@@ -3,6 +3,11 @@ module Diaspora
     extend ActiveSupport::Concern
 
     included do
+      before_create do
+        # TODO: remove when most of the posts can handle the new syntax
+        self.text = Diaspora::Mentionable.backport_mention_syntax(text) if text
+      end
+
       after_create :create_mentions
       has_many :mentions, as: :mentions_container, dependent: :destroy
     end

spec/lib/diaspora/mentionable_spec.rb

@@ -175,4 +175,29 @@ STR
       expect(txt).to include(@mention_b)
     end
   end
+
+  describe ".backport_mention_syntax" do
+    it "replaces the new syntax with the old syntax" do
+      text = "mention @{#{@people[0].diaspora_handle}} text"
+      expected_text = "mention @{#{@people[0].name}; #{@people[0].diaspora_handle}} text"
+      expect(Diaspora::Mentionable.backport_mention_syntax(text)).to eq(expected_text)
+    end
+
+    it "does not change the text, when the mention includes a name" do
+      text = "mention @{#{@names[0]}; #{@people[0].diaspora_handle}} text"
+      expect(Diaspora::Mentionable.backport_mention_syntax(text)).to eq(text)
+    end
+
+    it "does not change the text, when the person is not found" do
+      text = "mention @{non_existing_user@example.org} text"
+      expect(Person).to receive(:find_or_fetch_by_identifier).with("non_existing_user@example.org").and_return(nil)
+      expect(Diaspora::Mentionable.backport_mention_syntax(text)).to eq(text)
+    end
+
+    it "does not change the text, when the diaspora ID is invalid" do
+      text = "mention @{invalid_diaspora_id} text"
+      expect(Person).not_to receive(:find_or_fetch_by_identifier)
+      expect(Diaspora::Mentionable.backport_mention_syntax(text)).to eq(text)
+    end
+  end
 end

spec/shared_behaviors/mentions_container.rb

@@ -10,6 +10,16 @@ shared_examples_for "it is mentions container" do
     target
   }
 
+  describe ".before_create" do
+    it "backports mention syntax to old syntax" do
+      text = "mention @{#{people[0].diaspora_handle}} text"
+      expected_text = "mention @{#{people[0].name}; #{people[0].diaspora_handle}} text"
+      obj = FactoryGirl.build(described_class.to_s.underscore.to_sym, text: text, author: alice.person)
+      obj.save
+      expect(obj.text).to eq(expected_text)
+    end
+  end
+
   describe ".after_create" do
     it "calls create_mentions" do
       expect(target).to receive(:create_mentions).and_call_original