Resolve "Can't activate approvals: The form contains the following error:...

Resolve "Can't activate approvals: The form contains the following error: Approver groups is invalid"

app/assets/javascripts/approvers_select.js

@@ -147,7 +147,7 @@ export default class ApproversSelect {
   }
 
   static saveApprovers(fieldName) {
-    const $input = $(`[name="${fieldName}"]`);
+    const $input = window.$(`[name="${fieldName}"]`);
     const newValue = $input.val();
     const $loadWrapper = $('.load-wrapper');
     const $approverSelect = $('.js-select-user-and-group');
@@ -158,7 +158,7 @@ export default class ApproversSelect {
 
     const $form = $('.js-add-approvers').closest('form');
     $loadWrapper.removeClass('hidden');
-    $.ajax({
+    window.$.ajax({
       url: $form.attr('action'),
       type: 'POST',
       data: {
@@ -167,7 +167,7 @@ export default class ApproversSelect {
       },
       success: ApproversSelect.updateApproverList,
       complete() {
-        $input.val('val', '');
+        $input.val('');
         $approverSelect.select2('val', '');
         $loadWrapper.addClass('hidden');
       },

spec/javascripts/approvers_select_spec.js

+import ApproversSelect from '~/approvers_select';
+import ClassSpecHelper from './helpers/class_spec_helper';
+
+describe('ApproversSelect', () => {
+  describe('saveApprovers', () => {
+    let complete;
+    const $input = jasmine.createSpyObj('$input', ['val']);
+
+    beforeEach(() => {
+      spyOn(window, '$').and.returnValue($input);
+      spyOn(window.$, 'ajax').and.callFake((options) => {
+        complete = options.complete;
+      });
+
+      $input.val.and.returnValue('newValue');
+
+      ApproversSelect.saveApprovers('fieldName');
+    });
+
+    ClassSpecHelper.itShouldBeAStaticMethod(ApproversSelect, 'saveApprovers');
+
+    describe('when request completes', () => {
+      it('should empty the $input value', () => {
+        $input.val.calls.reset();
+
+        complete();
+
+        expect($input.val).toHaveBeenCalledWith('');
+      });
+    });
+  });
+});