Adds verification in case the endpoint already has `.json`

app/assets/javascripts/commit/pipelines/pipelines_service.js.es6

@@ -8,8 +8,23 @@
  * Uses Vue.Resource
  */
 class PipelinesService {
-  constructor(endpoint) {
-    this.pipelines = Vue.resource(`${endpoint}.json`);
+
+  /**
+   * FIXME: The url provided to request the pipelines in the new merge request
+   * page already has `.json`.
+   * This should be fixed when the endpoint is improved.
+   *
+   * @param  {String} root
+   */
+  constructor(root) {
+    let endpoint;
+
+    if (root.indexOf('.json') === -1) {
+      endpoint = `${root}.json`;
+    } else {
+      endpoint = root;
+    }
+    this.pipelines = Vue.resource(endpoint);
   }
 
   /**

spec/features/merge_requests/create_new_mr_spec.rb

 require 'spec_helper'
 
 feature 'Create New Merge Request', feature: true, js: true do
+  include WaitForVueResource
+
   let(:user) { create(:user) }
   let(:project) { create(:project, :public) }
 
@@ -99,6 +101,7 @@ feature 'Create New Merge Request', feature: true, js: true do
 
       page.within('.merge-request') do
         click_link 'Pipelines'
+        wait_for_vue_resource
 
         expect(page).to have_content "##{pipeline.id}"
       end