Merge branch '35475-lazy-diff' into 'master'

Resolve "Projects::MergeRequestsController#show is slow (implement skeleton loading)"

Closes #35475

See merge request gitlab-org/gitlab-ce!15200

2 files changed, 15 insertions, 2 deletions

diff --git a/spec/features/merge_request/user_resolves_diff_notes_and_discussions_resolve_spec.rb b/spec/features/merge_request/user_resolves_diff_notes_and_discussions_resolve_spec.rb
index 3e83a549682..b4ad4b64d8e 100644
--- a/spec/features/merge_request/user_resolves_diff_notes_and_discussions_resolve_spec.rb
+++ b/spec/features/merge_request/user_resolves_diff_notes_and_discussions_resolve_spec.rb
@@ -108,6 +108,7 @@ describe 'Merge request > User resolves diff notes and discussions', :js do
           it 'shows resolved discussion when toggled' do
             find(".timeline-content .discussion[data-discussion-id='#{note.discussion_id}'] .discussion-toggle-button").click
 
+            expect(page.find(".line-holder-placeholder")).to be_visible
             expect(page.find(".timeline-content #note_#{note.id}")).to be_visible
           end
         end
diff --git a/spec/features/merge_request/user_scrolls_to_note_on_load_spec.rb b/spec/features/merge_request/user_scrolls_to_note_on_load_spec.rb
index 8a834adbf17..565e375600b 100644
--- a/spec/features/merge_request/user_scrolls_to_note_on_load_spec.rb
+++ b/spec/features/merge_request/user_scrolls_to_note_on_load_spec.rb
@@ -5,15 +5,18 @@ describe 'Merge request > User scrolls to note on load', :js do
   let(:user) { project.creator }
   let(:merge_request) { create(:merge_request, source_project: project, author: user) }
   let(:note) { create(:diff_note_on_merge_request, noteable: merge_request, project: project) }
+  let(:resolved_note) { create(:diff_note_on_merge_request, :resolved, noteable: merge_request, project: project) }
   let(:fragment_id) { "#note_#{note.id}" }
+  let(:collapsed_fragment_id) { "#note_#{resolved_note.id}" }
 
   before do
     sign_in(user)
     page.current_window.resize_to(1000, 300)
-    visit "#{project_merge_request_path(project, merge_request)}#{fragment_id}"
   end
 
-  it 'scrolls down to fragment' do
+  it 'scrolls note into view' do
+    visit "#{project_merge_request_path(project, merge_request)}#{fragment_id}"
+
     page_height = page.current_window.size[1]
     page_scroll_y = page.evaluate_script("window.scrollY")
     fragment_position_top = page.evaluate_script("Math.round($('#{fragment_id}').offset().top)")
@@ -23,4 +26,13 @@ describe 'Merge request > User scrolls to note on load', :js do
     expect(fragment_position_top).to be >= page_scroll_y
     expect(fragment_position_top).to be < (page_scroll_y + page_height)
   end
+
+  it 'expands collapsed notes' do
+    visit "#{project_merge_request_path(project, merge_request)}#{collapsed_fragment_id}"
+    note_element = find(collapsed_fragment_id)
+    note_container = note_element.ancestor('.js-toggle-container')
+
+    expect(note_element.visible?).to eq true
+    expect(note_container.find('.line_content.noteable_line.old', match: :first).visible?).to eq true
+  end
 end