Comment on any expanded diff line on MRs

2 files changed, 18 insertions, 1 deletions

diff --git a/app/controllers/projects/blob_controller.rb b/app/controllers/projects/blob_controller.rb
index c02ec407262..0718658cd48 100644
--- a/app/controllers/projects/blob_controller.rb
+++ b/app/controllers/projects/blob_controller.rb
@@ -122,7 +122,7 @@ class Projects::BlobController < Projects::ApplicationController
     @lines.map! do |line|
       # These are marked as context lines but are loaded from blobs.
       # We also have context lines loaded from diffs in other places.
-      diff_line = Gitlab::Diff::Line.new(line, 'context', nil, nil, nil)
+      diff_line = Gitlab::Diff::Line.new(line, expanded_diff_line_type, nil, nil, nil)
       diff_line.rich_text = line
       diff_line
     end
@@ -132,6 +132,11 @@ class Projects::BlobController < Projects::ApplicationController
     render json: DiffLineSerializer.new.represent(@lines)
   end
 
+  def expanded_diff_line_type
+    # Context lines can't receive comments.
+    Feature.enabled?(:comment_in_any_diff_line, @project) ? nil : 'context'
+  end
+
   def add_match_line
     return unless @form.unfold?
 
diff --git a/app/controllers/projects/merge_requests/diffs_controller.rb b/app/controllers/projects/merge_requests/diffs_controller.rb
index 5307cd0720a..b3d77335c2a 100644
--- a/app/controllers/projects/merge_requests/diffs_controller.rb
+++ b/app/controllers/projects/merge_requests/diffs_controller.rb
@@ -22,6 +22,12 @@ class Projects::MergeRequests::DiffsController < Projects::MergeRequests::Applic
 
   def render_diffs
     @environment = @merge_request.environments_for(current_user).last
+    notes_grouped_by_path = renderable_notes.group_by { |note| note.position.file_path }
+
+    @diffs.diff_files.each do |diff_file|
+      notes = notes_grouped_by_path.fetch(diff_file.file_path, [])
+      notes.each { |note| diff_file.unfold_diff_lines(note.position) }
+    end
 
     @diffs.write_cache
 
@@ -108,4 +114,10 @@ class Projects::MergeRequests::DiffsController < Projects::MergeRequests::Applic
     @grouped_diff_discussions = @merge_request.grouped_diff_discussions(@compare.diff_refs)
     @notes = prepare_notes_for_rendering(@grouped_diff_discussions.values.flatten.flat_map(&:notes), @merge_request)
   end
+
+  def renderable_notes
+    define_diff_comment_vars unless @notes
+
+    @notes
+  end
 end