Merge branch 'hoopes/gitlab-ce-21027-add-diff-hunks-to-notification-emails' into 'master'

Add diff hunks to notification emails

Add diff hunks to notification emails. Continued from https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/5855 - thanks @hoopes!

This also fixes an issue where the + / - prefixes were missing from diffs in emails.

Screenshots (from my browser) of the HTML emails, along with text screenshots :stuck_out_tongue:

![image](/uploads/cb31400becf5149d40c8bb98a655aa93/image.png)

```
New comment for Merge Request !1 on app/views/admin/builds/index.html.haml:

http://localhost:3000/gitlab-org/gitlab-ce/merge_requests/1#note_1023

>          Finished

This is a comment at the top of a match section.
```

![image](/uploads/704dd3845797530697a27f5c1953c053/image.png)

```
New comment for Merge Request !1 on app/views/admin/builds/index.html.haml:

http://localhost:3000/gitlab-org/gitlab-ce/merge_requests/1#note_1022

>          Finished
>          %span.badge.js-running-count= @all_builds.finished.count(:id)
>  
> -    %li{class: ('active' if @scope == 'all')}
> -      = link_to admin_builds_path(scope: :all) do
> -        All
> -        %span.badge.js-totalbuilds-count= @all_builds.count(:id)
> -
>  .gray-content-block
>    #{(@scope || 'running').capitalize} builds
>  

This is a comment at the bottom of a match section.
```

![image](/uploads/4063f3d9738aea8ebf3c0e690d0eddee/image.png)

```
New comment for Merge Request !1 on app/views/admin/builds/index.html.haml:

http://localhost:3000/gitlab-org/gitlab-ce/merge_requests/1#note_1024

>          = link_to 'Cancel all', cancel_all_admin_builds_path, data: { confirm: 'Are you sure?' }, class: 'btn btn-danger', method: :post
>  
>    %ul.center-top-menu
> -    %li{class: ('active' if @scope.nil?)}
> +    %li{class: ('active' if @scope == 'all')}
>        = link_to admin_builds_path do
> +        All

This is a comment with some deleted and added lines above it.
```

Closes #21027, closes #24340.

See merge request !7660

16 files changed, 154 insertions, 35 deletions

diff --git a/app/assets/stylesheets/mailers/repository_push_email.scss b/app/assets/stylesheets/mailers/highlighted_diff_email.scss
index 8d1a6020ca4..8d1a6020ca4 100644
--- a/app/assets/stylesheets/mailers/repository_push_email.scss
+++ b/app/assets/stylesheets/mailers/highlighted_diff_email.scss
diff --git a/app/mailers/emails/notes.rb b/app/mailers/emails/notes.rb
index 96116e916dd..0d20c9092c4 100644
--- a/app/mailers/emails/notes.rb
+++ b/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
diff --git a/app/models/discussion.rb b/app/models/discussion.rb
index de06c13481a..75a85563235 100644
--- a/app/models/discussion.rb
+++ b/app/models/discussion.rb
@@ -25,7 +25,12 @@ class Discussion
             to: :last_resolved_note,
             allow_nil: true
 
-  delegate :blob, :highlighted_diff_lines, to: :diff_file, allow_nil: true
+  delegate  :blob,
+            :highlighted_diff_lines,
+            :diff_lines,
+
+            to: :diff_file,
+            allow_nil: true
 
   def self.for_notes(notes)
     notes.group_by(&:discussion_id).values.map { |notes| new(notes) }
@@ -159,10 +164,11 @@ class Discussion
   end
 
   # Returns an array of at most 16 highlighted lines above a diff note
-  def truncated_diff_lines
+  def truncated_diff_lines(highlight: true)
+    lines = highlight ? highlighted_diff_lines : diff_lines
     prev_lines = []
 
-    highlighted_diff_lines.each do |line|
+    lines.each do |line|
       if line.meta?
         prev_lines.clear
       else
diff --git a/app/views/notify/_note_message.text.erb b/app/views/notify/_note_message.text.erb
new file mode 100644
index 00000000000..f82cbc9a3fc
--- /dev/null
+++ b/app/views/notify/_note_message.text.erb
@@ -0,0 +1,5 @@
+<% if current_application_settings.email_author_in_body %>
+  <%= @note.author_name %> wrote:
+<% end -%>
+
+<%= @note.note %>
diff --git a/app/views/notify/_note_mr_or_commit_email.html.haml b/app/views/notify/_note_mr_or_commit_email.html.haml
new file mode 100644
index 00000000000..edf8dfe7e9e
--- /dev/null
+++ b/app/views/notify/_note_mr_or_commit_email.html.haml
@@ -0,0 +1,18 @@
+= content_for :head do
+  = stylesheet_link_tag 'mailers/highlighted_diff_email'
+
+New comment
+
+- if @discussion && @discussion.diff_file
+  on
+  = 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'
diff --git a/app/views/notify/_note_mr_or_commit_email.text.erb b/app/views/notify/_note_mr_or_commit_email.text.erb
new file mode 100644
index 00000000000..b4fcdf6b1e9
--- /dev/null
+++ b/app/views/notify/_note_mr_or_commit_email.text.erb
@@ -0,0 +1,8 @@
+<% if @discussion && @discussion.diff_file -%>
+ on <%= @note.diff_file.file_path -%>
+<% end -%>:
+
+<%= url %>
+
+<%= render 'simple_diff' if @discussion -%>
+<%= render 'note_message' %>
diff --git a/app/views/notify/_simple_diff.text.erb b/app/views/notify/_simple_diff.text.erb
new file mode 100644
index 00000000000..c28d1cc34d3
--- /dev/null
+++ b/app/views/notify/_simple_diff.text.erb
@@ -0,0 +1,3 @@
+<% @discussion.truncated_diff_lines(highlight: false).each do |line| %>
+> <%= line.text %>
+<% end %>
diff --git a/app/views/notify/note_commit_email.html.haml b/app/views/notify/note_commit_email.html.haml
index 1d961e4424c..0a650e3b2ca 100644
--- a/app/views/notify/note_commit_email.html.haml
+++ b/app/views/notify/note_commit_email.html.haml
@@ -1,2 +1,2 @@
-= render 'note_message'
-
+%p.details
+  = render 'note_mr_or_commit_email'
diff --git a/app/views/notify/note_commit_email.text.erb b/app/views/notify/note_commit_email.text.erb
index aaeaf5fdf73..6aa085a172e 100644
--- a/app/views/notify/note_commit_email.text.erb
+++ b/app/views/notify/note_commit_email.text.erb
@@ -1,9 +1,2 @@
-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 %>
-
-<%= @note.note %>
-
+New comment for Commit <%= @commit.short_id -%>
+<%= render partial: 'note_mr_or_commit_email', locals: { url: @target_url } %>
diff --git a/app/views/notify/note_merge_request_email.html.haml b/app/views/notify/note_merge_request_email.html.haml
index ea7e3d199fd..0a650e3b2ca 100644
--- a/app/views/notify/note_merge_request_email.html.haml
+++ b/app/views/notify/note_merge_request_email.html.haml
@@ -1,7 +1,2 @@
-- if @note.diff_note? && @note.diff_file
-  %p.details
-    New comment on diff for
-    = link_to @note.diff_file.file_path, @target_url
-    \:
-
-= render 'note_message'
+%p.details
+  = render 'note_mr_or_commit_email'
diff --git a/app/views/notify/note_merge_request_email.text.erb b/app/views/notify/note_merge_request_email.text.erb
index 8cdab63829e..2ce64c494cf 100644
--- a/app/views/notify/note_merge_request_email.text.erb
+++ b/app/views/notify/note_merge_request_email.text.erb
@@ -1,9 +1,2 @@
-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 %>
-
-<%= @note.note %>
-
+New comment for Merge Request <%= @merge_request.to_reference -%>
+<%= render partial: 'note_mr_or_commit_email', locals: { url: @target_url }%>
diff --git a/app/views/notify/repository_push_email.html.haml b/app/views/notify/repository_push_email.html.haml
index 307c5a11206..25883de257c 100644
--- a/app/views/notify/repository_push_email.html.haml
+++ b/app/views/notify/repository_push_email.html.haml
@@ -1,5 +1,5 @@
 = content_for :head do
-  = stylesheet_link_tag 'mailers/repository_push_email'
+  = stylesheet_link_tag 'mailers/highlighted_diff_email'
 
 %h3
   #{@message.author_name} #{@message.action_name} #{@message.ref_type} #{@message.ref_name}
diff --git a/app/views/projects/diffs/_line.html.haml b/app/views/projects/diffs/_line.html.haml
index a3e4b5b777e..16c96b66714 100644
--- a/app/views/projects/diffs/_line.html.haml
+++ b/app/views/projects/diffs/_line.html.haml
@@ -25,7 +25,7 @@
         %a{href: "##{line_code}", data: { linenumber: link_text }}
     %td.line_content.noteable_line{ class: type, data: (diff_view_line_data(line_code, diff_file.position(line), type) unless plain) }<
       - if email
-        %pre= diff_line_content(line.text)
+        %pre= line.text
       - else
         = diff_line_content(line.text)
 
diff --git a/changelogs/unreleased/hoopes-gitlab-ce-21027-add-diff-hunks-to-notification-emails.yml b/changelogs/unreleased/hoopes-gitlab-ce-21027-add-diff-hunks-to-notification-emails.yml
new file mode 100644
index 00000000000..73d8a52e001
--- /dev/null
+++ b/changelogs/unreleased/hoopes-gitlab-ce-21027-add-diff-hunks-to-notification-emails.yml
@@ -0,0 +1,4 @@
+---
+title: Add git diff context to notifications of new notes on merge requests
+merge_request:
+author: Heidi Hoopes
diff --git a/spec/mailers/notify_spec.rb b/spec/mailers/notify_spec.rb
index 932a5dc4862..39ba48f61cb 100644
--- a/spec/mailers/notify_spec.rb
+++ b/spec/mailers/notify_spec.rb
@@ -50,7 +50,7 @@ describe Notify do
 
           context 'when enabled email_author_in_body' do
             before do
-              allow_any_instance_of(ApplicationSetting).to receive(:email_author_in_body).and_return(true)
+              stub_application_setting(email_author_in_body: true)
             end
 
             it 'contains a link to note author' do
@@ -229,7 +229,7 @@ describe Notify do
 
           context 'when enabled email_author_in_body' do
             before do
-              allow_any_instance_of(ApplicationSetting).to receive(:email_author_in_body).and_return(true)
+              stub_application_setting(email_author_in_body: true)
             end
 
             it 'contains a link to note author' do
@@ -607,7 +607,7 @@ describe Notify do
 
         context 'when enabled email_author_in_body' do
           before do
-            allow_any_instance_of(ApplicationSetting).to receive(:email_author_in_body).and_return(true)
+            stub_application_setting(email_author_in_body: true)
           end
 
           it 'contains a link to note author' do
@@ -686,6 +686,79 @@ 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=\"p\">}<\/span><\/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
+            stub_application_setting(email_author_in_body: 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 '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 'it should show Gmail Actions View Merge request link'
+        it_behaves_like 'an unsubscribeable thread'
+      end
+    end
   end
 
   context 'for a group' do
diff --git a/spec/models/discussion_spec.rb b/spec/models/discussion_spec.rb
index 0142706d140..2a67c60b978 100644
--- a/spec/models/discussion_spec.rb
+++ b/spec/models/discussion_spec.rb
@@ -590,4 +590,23 @@ describe Discussion, model: true do
       end
     end
   end
+
+  describe "#truncated_diff_lines" do
+    let(:truncated_lines) { subject.truncated_diff_lines }
+
+    context "when diff is greater than allowed number of truncated diff lines " do
+      it "returns fewer lines"  do
+        expect(subject.diff_lines.count).to be > described_class::NUMBER_OF_TRUNCATED_DIFF_LINES
+
+        expect(truncated_lines.count).to be <= described_class::NUMBER_OF_TRUNCATED_DIFF_LINES
+      end
+    end
+
+    context "when some diff lines are meta" do
+      it "returns no meta lines"  do
+        expect(subject.diff_lines).to include(be_meta)
+        expect(truncated_lines).not_to include(be_meta)
+      end
+    end
+  end
 end