Add indication for closed or merged issuables in GFMadam-finish-5993-closed-issuable

Example: for issues that are closed, the links will now show '[closed]'
following the issue number. This is done as post-process after the markdown has
been loaded from the cache as the status of the issue may change between
the cache being populated and the content being displayed.

In order to avoid N+1 queries problem when rendering notes ObjectRenderer
populates the cache of referenced issuables for all notes at once,
before the post processing phase.

As a part of this change, the Banzai BaseParser#grouped_objects_for_nodes
method has been refactored to return a Hash utilising the node itself as the
key, since this was a common pattern of usage for this method.

3 files changed, 34 insertions, 5 deletions

diff --git a/spec/lib/banzai/reference_parser/base_parser_spec.rb b/spec/lib/banzai/reference_parser/base_parser_spec.rb
index aa127f0179d..a3141894c74 100644
--- a/spec/lib/banzai/reference_parser/base_parser_spec.rb
+++ b/spec/lib/banzai/reference_parser/base_parser_spec.rb
@@ -92,16 +92,26 @@ describe Banzai::ReferenceParser::BaseParser, lib: true do
   end
 
   describe '#grouped_objects_for_nodes' do
-    it 'returns a Hash grouping objects per ID' do
-      nodes = [double(:node)]
+    it 'returns a Hash grouping objects per node' do
+      link = double(:link)
+
+      expect(link).to receive(:has_attribute?).
+        with('data-user').
+        and_return(true)
+
+      expect(link).to receive(:attr).
+        with('data-user').
+        and_return(user.id.to_s)
+
+      nodes = [link]
 
       expect(subject).to receive(:unique_attribute_values).
         with(nodes, 'data-user').
-        and_return([user.id])
+        and_return([user.id.to_s])
 
       hash = subject.grouped_objects_for_nodes(nodes, User, 'data-user')
 
-      expect(hash).to eq({ user.id => user })
+      expect(hash).to eq({ link => user })
     end
 
     it 'returns an empty Hash when the list of nodes is empty' do
diff --git a/spec/lib/banzai/reference_parser/issue_parser_spec.rb b/spec/lib/banzai/reference_parser/issue_parser_spec.rb
index 6873b7b85f9..7031c47231c 100644
--- a/spec/lib/banzai/reference_parser/issue_parser_spec.rb
+++ b/spec/lib/banzai/reference_parser/issue_parser_spec.rb
@@ -67,6 +67,16 @@ describe Banzai::ReferenceParser::IssueParser, lib: true do
           expect(subject.referenced_by([])).to eq([])
         end
       end
+
+      context 'when issue with given ID does not exist' do
+        before do
+          link['data-issue'] = '-1'
+        end
+
+        it 'returns an empty Array' do
+          expect(subject.referenced_by([link])).to eq([])
+        end
+      end
     end
   end
 
@@ -75,7 +85,7 @@ describe Banzai::ReferenceParser::IssueParser, lib: true do
       link['data-issue'] = issue.id.to_s
       nodes = [link]
 
-      expect(subject.issues_for_nodes(nodes)).to eq({ issue.id => issue })
+      expect(subject.issues_for_nodes(nodes)).to eq({ link => issue })
     end
   end
 end
diff --git a/spec/lib/banzai/reference_parser/user_parser_spec.rb b/spec/lib/banzai/reference_parser/user_parser_spec.rb
index 31ca9d27b0b..4ec998efe53 100644
--- a/spec/lib/banzai/reference_parser/user_parser_spec.rb
+++ b/spec/lib/banzai/reference_parser/user_parser_spec.rb
@@ -180,6 +180,15 @@ describe Banzai::ReferenceParser::UserParser, lib: true do
 
         expect(subject.nodes_user_can_reference(user, [link])).to eq([])
       end
+
+      it 'returns the nodes if the project attribute value equals the current project ID' do
+        other_user = create(:user)
+
+        link['data-project'] = project.id.to_s
+        link['data-author'] = other_user.id.to_s
+
+        expect(subject.nodes_user_can_reference(user, [link])).to eq([link])
+      end
     end
 
     context 'when the link does not have a data-author attribute' do