Make tasklist:changed test in merge_request_spec.js async

spec/javascripts/merge_request_spec.js

@@ -19,17 +19,24 @@ import IssuablesHelper from '~/helpers/issuables_helper';
         $('input[type=checkbox]').attr('checked', true)[0].dispatchEvent(changeEvent);
         return expect($('.js-task-list-field').val()).toBe('- [x] Task List Item');
       });
-      return it('submits an ajax request on tasklist:changed', function() {
-        spyOn(jQuery, 'ajax').and.callFake(function(req) {
+
+      it('submits an ajax request on tasklist:changed', (done) => {
+        spyOn(jQuery, 'ajax').and.callFake((req) => {
           expect(req.type).toBe('PATCH');
           expect(req.url).toBe(`${gl.TEST_HOST}/frontend-fixtures/merge-requests-project/merge_requests/1.json`);
-          return expect(req.data.merge_request.description).not.toBe(null);
+          expect(req.data.merge_request.description).not.toBe(null);
+          done();
         });
-        return $('.js-task-list-field').trigger('tasklist:changed');
+
+        $('.js-task-list-field').trigger('tasklist:changed');
       });
     });
 
     describe('class constructor', () => {
+      beforeEach(() => {
+        spyOn(jQuery, 'ajax').and.stub();
+      });
+
       it('calls .initCloseReopenReport', () => {
         spyOn(IssuablesHelper, 'initCloseReopenReport');