Merge branch '350217-merge-request-edit-language-fix' into 'master'

Add user's preferred language to cache key of MR title partial

See merge request gitlab-org/gitlab!78640

app/views/projects/merge_requests/_mr_title.html.haml

@@ -2,7 +2,7 @@
 - can_update_merge_request = can?(current_user, :update_merge_request, @merge_request)
 - can_reopen_merge_request = can?(current_user, :reopen_merge_request, @merge_request)
 - are_close_and_open_buttons_hidden = merge_request_button_hidden?(@merge_request, true) && merge_request_button_hidden?(@merge_request, false)
-- cache_key = [@project, @merge_request, can_update_merge_request, can_reopen_merge_request, are_close_and_open_buttons_hidden]
+- cache_key = [@project, @merge_request, can_update_merge_request, can_reopen_merge_request, are_close_and_open_buttons_hidden, current_user&.preferred_language]
 
 = cache(cache_key, expires_in: 1.day) do
   - if @merge_request.closed_or_merged_without_fork?

spec/features/merge_request/user_views_open_merge_request_spec.rb

@@ -128,4 +128,30 @@ RSpec.describe 'User views an open merge request' do
       expect(find("[data-testid='ref-name']")[:title]).to eq(source_branch)
     end
   end
+
+  context 'when user preferred language has changed', :use_clean_rails_memory_store_fragment_caching do
+    let(:project) { create(:project, :public, :repository) }
+    let(:user) { create(:user) }
+
+    before do
+      project.add_maintainer(user)
+      sign_in(user)
+    end
+
+    it 'renders edit button in preferred language' do
+      visit(merge_request_path(merge_request))
+
+      page.within('.detail-page-header-actions') do
+        expect(page).to have_link('Edit')
+      end
+
+      user.update!(preferred_language: 'de')
+
+      visit(merge_request_path(merge_request))
+
+      page.within('.detail-page-header-actions') do
+        expect(page).to have_link('Bearbeiten')
+      end
+    end
+  end
 end