Ensure notes are replaced on a merge request diff when they're updated

app/assets/javascripts/notes.js.coffee

@@ -286,7 +286,7 @@ class @Notes
     $html.find('.js-task-list-container').taskList('enable')
 
     # Find the note's `li` element by ID and replace it with the updated HTML
-    $note_li = $("#note_#{note.id}")
+    $note_li = $('.note-row-' + note.id)
     $note_li.replaceWith($html)
 
   ###

features/project/merge_requests.feature

@@ -83,6 +83,16 @@ Feature: Project Merge Requests
     And I switch to the merge request's comments tab
     Then I should see a discussion has started on diff
 
+  @javascript
+  Scenario: I edit a comment on a merge request diff
+    Given project "Shop" have "Bug NS-05" open merge request with diffs inside
+    And I visit merge request page "Bug NS-05"
+    And I click on the Changes tab
+    And I leave a comment like "Line is wrong" on diff
+    And I change the comment "Line is wrong" to "Typo, please fix" on diff
+    Then I should not see a diff comment saying "Line is wrong"
+    And I should see a diff comment saying "Typo, please fix"
+
   @javascript
   Scenario: I comment on a line of a commit in merge request
     Given project "Shop" have "Bug NS-05" open merge request with diffs inside

features/steps/project/merge_requests.rb

@@ -186,6 +186,31 @@ class Spinach::Features::ProjectMergeRequests < Spinach::FeatureSteps
     leave_comment "Line is wrong"
   end
 
+  step 'I change the comment "Line is wrong" to "Typo, please fix" on diff' do
+    page.within('.diff-file:nth-of-type(5) .note') do
+      find('.js-note-edit').click
+
+      page.within('.current-note-edit-form', visible: true) do
+        fill_in 'note_note', with: 'Typo, please fix'
+        click_button 'Save Comment'
+      end
+
+      expect(page).not_to have_button 'Save Comment', disabled: true, visible: true
+    end
+  end
+
+  step 'I should not see a diff comment saying "Line is wrong"' do
+    page.within('.diff-file:nth-of-type(5) .note') do
+      expect(page).not_to have_visible_content 'Line is wrong'
+    end
+  end
+
+  step 'I should see a diff comment saying "Typo, please fix"' do
+    page.within('.diff-file:nth-of-type(5) .note') do
+      expect(page).to have_visible_content 'Typo, please fix'
+    end
+  end
+
   step 'I should see a discussion has started on diff' do
     page.within(".notes .discussion") do
       page.should have_content "#{current_user.name} started a discussion"