Add new template to handle both commit & mr notes

Currently comments on commits and merge requests do not require merge request- or commit-specific information, but can use the same template. Rather than change the method which calls the template, I opted to keep the templates separate and create a new template to highlight their identicality, while preserving the option to distinguish them from each other in the future.

Also removed some of the inconsistencies between text and html email versions.

Still needed is a text-only version of git diffs and testing.

app/mailers/emails/notes.rb

@@ -4,6 +4,7 @@ module Emails
       setup_note_mail(note_id, recipient_id)
 
       @commit = @note.noteable
+      @discussion = @note.to_discussion if @note.diff_note?
       @target_url = namespace_project_commit_url(*note_target_url_options)
 
       mail_answer_thread(@commit,
@@ -24,6 +25,7 @@ module Emails
       setup_note_mail(note_id, recipient_id)
 
       @merge_request = @note.noteable
+      @discussion = @note.to_discussion if @note.diff_note?
       @target_url = namespace_project_merge_request_url(*note_target_url_options)
       mail_answer_thread(@merge_request, note_thread_options(recipient_id))
     end

app/views/notify/_note_mr_or_commit_email.html.haml

+= content_for :head do
+  = stylesheet_link_tag 'mailers/highlighted_diff_email'
+
+- if note.diff_note? && note.diff_file
+  = link_to note.diff_file.file_path, @target_url, class: 'details'
+  \:
+
+  %table
+    = render partial: "projects/diffs/line",
+      collection: discussion.truncated_diff_lines,
+      as: :line,
+      locals: { diff_file: note.diff_file,
+      plain: true,
+      email: true }
+
+= render 'note_message'

app/views/notify/note_commit_email.html.haml

-= render 'note_message'
-
+%p.details
+  New comment for Commit
+  = @commit.short_id
+  on
+  = render partial: 'note_mr_or_commit_email',
+    locals: { note: @note,
+    discussion: @discussion}

app/views/notify/note_commit_email.text.erb

@@ -2,8 +2,8 @@ New comment for Commit <%= @commit.short_id %>
 
 <%= url_for(namespace_project_commit_url(@note.project.namespace, @note.project, id: @commit.id, anchor: "note_#{@note.id}")) %>
 
-
-Author: <%= @note.author_name %>
+<% if current_application_settings.email_author_in_body %>
+  <%= @note.author_name %> wrote:
+<% end %>
 
 <%= @note.note %>
-

app/views/notify/note_merge_request_email.html.haml

-= content_for :head do
-  = stylesheet_link_tag 'mailers/highlighted_diff_email'
-
-- if @note.diff_note? && @note.diff_file
-  %p.details
-    New comment on diff for
-    = link_to @note.diff_file.file_path, @target_url
-    \:
-
-    .diff-content.code.js-syntax-highlight
-      %table
-        - Discussion.new([@note]).truncated_diff_lines.each do |line|
-          = render "projects/diffs/line", line: line, diff_file: @note.diff_file, plain: true
-
-= render 'note_message'
+%p.details
+  New comment for Merge Request
+  = @merge_request.to_reference
+  on
+  = render partial: 'note_mr_or_commit_email',
+    locals: { note: @note,
+    discussion: @discussion}

app/views/notify/note_merge_request_email.text.erb

@@ -2,8 +2,8 @@ New comment for Merge Request <%= @merge_request.to_reference %>
 
 <%= url_for(namespace_project_merge_request_url(@merge_request.target_project.namespace, @merge_request.target_project, @merge_request, anchor: "note_#{@note.id}")) %>
 
-
-<%= @note.author_name %>
+<% if current_application_settings.email_author_in_body %>
+  <%= @note.author_name %> wrote:
+<% end %>
 
 <%= @note.note %>
-

spec/mailers/notify_spec.rb

@@ -580,11 +580,9 @@ describe Notify do
       let(:note_author) { create(:user, name: 'author_name') }
       let(:note) { create(:note, project: project, author: note_author) }
 
-      before do |example|
-        unless example.metadata[:skip_before]
+      before :each do
         allow(Note).to receive(:find).with(note.id).and_return(note)
       end
-      end
 
       shared_examples 'a note email' do
         it_behaves_like 'it should have Gmail Actions links'
@@ -665,19 +663,6 @@ describe Notify do
         end
       end
 
-      describe "on a merge request with diffs", :skip_before do
-        let(:merge_request) { create(:merge_request_with_diffs) }
-        let(:note_with_diff) {create(:diff_note_on_merge_request)}
-
-        before(:each) { allow(note_with_diff).to receive(:noteable).and_return(merge_request) }
-        subject { Notify.note_merge_request_email(recipient.id, note_with_diff.id) }
-
-        it 'includes diffs with character-level highlighting' do
-          expected_line_text = Discussion.new([note_with_diff]).truncated_diff_lines.first.text
-          is_expected.to have_body_text expected_line_text
-        end
-      end
-
       describe 'on an issue' do
         let(:issue) { create(:issue, project: project) }
         let(:note_on_issue_path) { namespace_project_issue_path(project.namespace, project, issue, anchor: "note_#{note.id}") }