Change diff highlight/truncate for reusability

Previously the `truncated_diff_lines` method for outputting a discussion diff took in already highlighted lines, which meant it wasn't reuseable for truncating ANY lines. In the way it was used, it also meant that for any email truncation, the whole diff was being highlighted before being truncated, meaning wasted time highlighting lines that wouldn't even be used (granted, they were being memoized, so perhaps this wasn't that great of an issue). I refactored truncation away from highlighting, in order to truncate formatted diffs for text templates in email, using `>`s to designate each line, but otherwise retaining the parsing already done to create `diff_lines`.

Additionally, while notes on merge requests or commits had already been tested, there was no existing test for notes on a diff on an MR or commit. Added mailer tests for such, and a unit test for truncating diff lines.

1 files changed, 79 insertions, 1 deletions

diff --git a/spec/mailers/notify_spec.rb b/spec/mailers/notify_spec.rb
index 932a5dc4862..a80eb114c17 100644
--- a/spec/mailers/notify_spec.rb
+++ b/spec/mailers/notify_spec.rb
@@ -646,7 +646,6 @@ describe Notify do
         before(:each) { allow(note).to receive(:noteable).and_return(merge_request) }
 
         subject { Notify.note_merge_request_email(recipient.id, note.id) }
-
         it_behaves_like 'a note email'
         it_behaves_like 'an answer to an existing thread with reply-by-email enabled' do
           let(:model) { merge_request }
@@ -686,6 +685,85 @@ describe Notify do
         end
       end
     end
+
+    context 'items that are noteable, emails for a note on a diff' do
+      let(:note_author) { create(:user, name: 'author_name') }
+
+      before :each do
+        allow(Note).to receive(:find).with(note.id).and_return(note)
+      end
+
+      shared_examples 'a note email on a diff' do  | model |
+        let(:note) { create(model, project: project, author: note_author) }
+
+        it "includes diffs with character-level highlighting" do
+          is_expected.to have_body_text /\<span class='idiff left right'>vars = {<\/span>/
+        end
+
+        it 'contains a link to the diff file' do
+          is_expected.to have_body_text /#{note.diff_file.file_path}/
+        end
+
+        it_behaves_like 'it should have Gmail Actions links'
+
+        it 'is sent as the author' do
+          sender = subject.header[:from].addrs[0]
+          expect(sender.display_name).to eq(note_author.name)
+          expect(sender.address).to eq(gitlab_sender)
+        end
+
+        it 'is sent to the given recipient' do
+          is_expected.to deliver_to recipient.notification_email
+        end
+
+        it 'contains the message from the note' do
+          is_expected.to have_body_text /#{note.note}/
+        end
+
+        it 'does not contain note author' do
+          is_expected.not_to have_body_text /wrote\:/
+        end
+
+        context 'when enabled email_author_in_body' do
+          before do
+            allow_any_instance_of(ApplicationSetting).to receive(:email_author_in_body).and_return(true)
+          end
+
+          it 'contains a link to note author' do
+            is_expected.to have_body_text note.author_name
+            is_expected.to have_body_text /wrote\:/
+          end
+        end
+      end
+
+      describe 'on a commit' do
+        let(:commit) { project.commit }
+        let(:note) { create(:diff_note_on_commit) }
+
+        subject { Notify.note_commit_email(recipient.id, note.id) }
+
+        it_behaves_like 'a note email on a diff', :diff_note_on_commit
+        # it_behaves_like 'an answer to an existing thread with reply-by-email enabled' do
+        #   let(:model) { commit }
+        # end
+        it_behaves_like 'it should show Gmail Actions View Commit link'
+        it_behaves_like 'a user cannot unsubscribe through footer link'
+      end
+
+      describe 'on a merge request' do
+        let(:merge_request) { create(:merge_request, source_project: project, target_project: project) }
+        let(:note) { create(:diff_note_on_merge_request) }
+
+        subject { Notify.note_merge_request_email(recipient.id, note.id) }
+
+        it_behaves_like 'a note email on a diff', :diff_note_on_merge_request
+        # it_behaves_like 'an answer to an existing thread with reply-by-email enabled' do
+        #   let(:model) { merge_request }
+        # end
+        it_behaves_like 'it should show Gmail Actions View Merge request link'
+        it_behaves_like 'an unsubscribeable thread'
+      end
+    end
   end
 
   context 'for a group' do