Added specs for merge request environment list

Ported from https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/1154

spec/features/merge_requests/widget_spec.rb

@@ -5,11 +5,15 @@ describe 'Merge request', :feature, :js do
 
   let(:project) { create(:project) }
   let(:user) { create(:user) }
+  let(:merge_request) { create(:merge_request, source_project: project) }
 
   before do
     project.team << [user, :master]
     login_as(user)
+  end
 
+  context 'new merge request' do
+    before do
       visit new_namespace_project_merge_request_path(
         project.namespace,
         project,
@@ -31,4 +35,23 @@ describe 'Merge request', :feature, :js do
 
       expect(page).to have_selector('.accept_merge_request')
     end
+  end
+
+  context 'view merge request' do
+    let!(:environment) { create(:environment, project: project) }
+    let!(:deployment) { create(:deployment, environment: environment, ref: 'feature', sha: merge_request.diff_head_sha) }
+
+    before do
+      visit namespace_project_merge_request_path(project.namespace, project, merge_request)
+    end
+
+    it 'shows environments link' do
+      wait_for_ajax
+
+      page.within('.mr-widget-heading') do
+        expect(page).to have_content("Deployed to #{environment.name}")
+        expect(find('.js-environment-link')[:href]).to include(environment.formatted_external_url)
+      end
+    end
+  end
 end