Handle namespaced models

We encountered issues with setting module headers for namespaced models.
These changes address this. We retain the namespacing, but transform the
classnames to make them into safe email headers.

1 files changed, 67 insertions, 0 deletions

diff --git a/spec/mailers/notify_spec.rb b/spec/mailers/notify_spec.rb
index dcc4b70a382..6cba7df114c 100644
--- a/spec/mailers/notify_spec.rb
+++ b/spec/mailers/notify_spec.rb
@@ -543,6 +543,73 @@ describe Notify do
       end
     end
 
+    describe '#mail_thread' do
+      set(:mail_thread_note) { create(:note) }
+
+      let(:headers) do
+        {
+          from: 'someone@test.com',
+          to: 'someone-else@test.com',
+          subject: 'something',
+          template_name: '_note_email' # re-use this for testing
+        }
+      end
+
+      let(:mailer) do
+        mailer = described_class.new
+        mailer.instance_variable_set(:@note, mail_thread_note)
+        mailer
+      end
+
+      context 'the model has no namespace' do
+        class TopLevelThing
+          include Referable
+          include Noteable
+
+          def to_reference(*_args)
+            'tlt-ref'
+          end
+
+          def id
+            'tlt-id'
+          end
+        end
+
+        subject do
+          mailer.send(:mail_thread, TopLevelThing.new, headers)
+        end
+
+        it 'has X-GitLab-Namespaced-Thing-ID header' do
+          expect(subject.header['X-GitLab-TopLevelThing-ID'].value).to eq('tlt-id')
+        end
+      end
+
+      context 'the model has a namespace' do
+        module Namespaced
+          class Thing
+            include Referable
+            include Noteable
+
+            def to_reference(*_args)
+              'some-reference'
+            end
+
+            def id
+              'some-id'
+            end
+          end
+        end
+
+        subject do
+          mailer.send(:mail_thread, Namespaced::Thing.new, headers)
+        end
+
+        it 'has X-GitLab-Namespaced-Thing-ID header' do
+          expect(subject.header['X-GitLab-Namespaced-Thing-ID'].value).to eq('some-id')
+        end
+      end
+    end
+
     context 'for issue notes' do
       let(:host) { Gitlab.config.gitlab.host }