Comment on any expanded diff line on MRs

4 files changed, 20 insertions, 6 deletions

diff --git a/app/services/merge_requests/reload_diffs_service.rb b/app/services/merge_requests/reload_diffs_service.rb
index b4d48fe92ad..d19cd1ac40f 100644
--- a/app/services/merge_requests/reload_diffs_service.rb
+++ b/app/services/merge_requests/reload_diffs_service.rb
@@ -29,10 +29,6 @@ module MergeRequests
 
     # rubocop: disable CodeReuse/ActiveRecord
     def clear_cache(new_diff)
-      # Executing the iteration we cache highlighted diffs for each diff file of
-      # MergeRequestDiff.
-      cacheable_collection(new_diff).write_cache
-
       # Remove cache for all diffs on this MR. Do not use the association on the
       # model, as that will interfere with other actions happening when
       # reloading the diff.
diff --git a/app/services/notes/base_service.rb b/app/services/notes/base_service.rb
new file mode 100644
index 00000000000..431ff6c11c4
--- /dev/null
+++ b/app/services/notes/base_service.rb
@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+module Notes
+  class BaseService < ::BaseService
+    def clear_noteable_diffs_cache(note)
+      noteable = note.noteable
+
+      if note.is_a?(DiffNote) &&
+          note.discussion_first_note? &&
+          note.position.unfolded_diff?(project.repository)
+        noteable.diffs.clear_cache
+      end
+    end
+  end
+end
diff --git a/app/services/notes/create_service.rb b/app/services/notes/create_service.rb
index 049e6c5a871..e03789e3ca9 100644
--- a/app/services/notes/create_service.rb
+++ b/app/services/notes/create_service.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 module Notes
-  class CreateService < ::BaseService
+  class CreateService < ::Notes::BaseService
     def execute
       merge_request_diff_head_sha = params.delete(:merge_request_diff_head_sha)
 
@@ -35,6 +35,7 @@ module Notes
 
       if !only_commands && note.save
         todo_service.new_note(note, current_user)
+        clear_noteable_diffs_cache(note)
       end
 
       if command_params.present?
diff --git a/app/services/notes/destroy_service.rb b/app/services/notes/destroy_service.rb
index 64e9accd97f..fa0c2c5c86b 100644
--- a/app/services/notes/destroy_service.rb
+++ b/app/services/notes/destroy_service.rb
@@ -1,11 +1,13 @@
 # frozen_string_literal: true
 
 module Notes
-  class DestroyService < BaseService
+  class DestroyService < ::Notes::BaseService
     def execute(note)
       TodoService.new.destroy_target(note) do |note|
         note.destroy
       end
+
+      clear_noteable_diffs_cache(note)
     end
   end
 end