Add one feature test.

features/project/merge_requests.feature

@@ -147,3 +147,13 @@ Feature: Project Merge Requests
     And I switch to the diff tab
     And I unfold diff
     Then I should see additional file lines
+
+  @javascript
+  Scenario: I show comments on a merge request side-by-side diff with comments in multiple files
+    Given project "Shop" have "Bug NS-05" open merge request with diffs inside
+    And I visit merge request page "Bug NS-05"
+    And I switch to the diff tab
+    And I leave a comment like "Line is correct" on line 12 of the first file
+    And I leave a comment like "Line is wrong" on line 39 of the second file
+    And I click Side-by-side Diff tab
+    Then I should see comments on the side-by-side diff page

features/steps/project/merge_requests.rb

@@ -250,6 +250,16 @@ class ProjectMergeRequests < Spinach::FeatureSteps
     expect(first('.text-file')).to have_content('.bundle')
   end
 
+  step 'I click Side-by-side Diff tab' do
+    click_link 'Side-by-side Diff'
+  end
+
+  step 'I should see comments on the side-by-side diff page' do
+    within '.files [id^=diff]:nth-child(1) .note-text' do
+      page.should have_visible_content "Line is correct"
+    end
+  end
+
   def project
     @project ||= Project.find_by!(name: "Shop")
   end