fetch mentioned people if they don't exist locally yet

fixes #4491

lib/diaspora/mentionable.rb

@@ -46,12 +46,11 @@ module Diaspora::Mentionable
   # @return [Array<Person>] array of people
   def self.people_from_string(msg_text)
     identifiers = msg_text.to_s.scan(REGEX).map do |match_str|
-      _, handle = mention_attrs(match_str.first)
-      handle
+      _, identifier = mention_attrs(match_str.first)
+      identifier if Validation::Rule::DiasporaId.new.valid_value?(identifier)
     end
 
-    return [] if identifiers.empty?
-    Person.where(diaspora_handle: identifiers)
+    identifiers.compact.uniq.map {|identifier| find_or_fetch_person_by_identifier(identifier) }.compact
   end
 
   # takes a message text and converts mentions for people that are not in the
@@ -81,6 +80,12 @@ module Diaspora::Mentionable
 
   private
 
+  private_class_method def self.find_or_fetch_person_by_identifier(identifier)
+    Person.find_or_fetch_by_identifier(identifier)
+  rescue DiasporaFederation::Discovery::DiscoveryError
+    nil
+  end
+
   # inline module for namespacing
   module MentionsInternal
     extend ::PeopleHelper

spec/lib/diaspora/mentionable_spec.rb

@@ -72,7 +72,7 @@ STR
   describe "#people_from_string" do
     it "extracts the mentioned people from the text" do
       ppl = Diaspora::Mentionable.people_from_string(@test_txt)
-      expect(ppl).to include(*@people)
+      expect(ppl).to match_array(@people)
     end
 
     describe "returns an empty array if nobody was found" do
@@ -82,7 +82,26 @@ STR
       end
 
       it "gets a post with invalid handles" do
-        ppl = Diaspora::Mentionable.people_from_string("@{a; xxx@xxx.xx} @{b; yyy@yyyy.yyy} @{...} @{bla; blubb}")
+        ppl = Diaspora::Mentionable.people_from_string("@{...} @{bla; blubb}")
+        expect(ppl).to be_empty
+      end
+
+      it "filters duplicate handles" do
+        ppl = Diaspora::Mentionable.people_from_string("@{a; #{alice.diaspora_handle}} @{a; #{alice.diaspora_handle}}")
+        expect(ppl).to eq([alice.person])
+      end
+
+      it "fetches unknown handles" do
+        person = FactoryGirl.build(:person)
+        expect(Person).to receive(:find_or_fetch_by_identifier).with("xxx@xxx.xx").and_return(person)
+        ppl = Diaspora::Mentionable.people_from_string("@{a; xxx@xxx.xx}")
+        expect(ppl).to eq([person])
+      end
+
+      it "handles DiscoveryError" do
+        expect(Person).to receive(:find_or_fetch_by_identifier).with("yyy@yyy.yy")
+          .and_raise(DiasporaFederation::Discovery::DiscoveryError)
+        ppl = Diaspora::Mentionable.people_from_string("@{b; yyy@yyy.yy}")
         expect(ppl).to be_empty
       end
     end

spec/lib/publisher_spec.rb

@@ -18,7 +18,7 @@ describe Publisher do
 
   describe '#text' do
     it 'is a formatted version of the prefill' do
-      p = Publisher.new(alice, :prefill => "@{alice; alice@pod.com}")
+      p = Publisher.new(alice, prefill: "@{alice; #{alice.diaspora_handle}}")
       expect(p.text).to eq("alice")
     end
   end