Specs for toggle Whitespaces Changes

spec/features/merge_requests/toggle_whitespace_changes.rb

+require 'spec_helper'
+
+feature 'Toggle Whitespace Changes', js: true, feature: true do
+  let(:merge_request) { create(:merge_request) }
+  let(:project) { merge_request.source_project }
+
+  before do
+    login_as :admin
+    visit diffs_namespace_project_merge_request_path(project.namespace, project, merge_request)
+  end
+
+  it 'should have a button to toggle whitespace changes' do
+    expect(page).to have_content "Hide whitespace changes"
+  end
+
+  describe 'clicking hide whitespace changes button' do
+    it 'should hide whitespace changes' do
+      find('a', text: "Hide whitespace changes").click
+      expect(page).to have_content "Show whitespace changes"
+    end
+  end
+end