Refactored Karma spec to Jest for mr_widget_auto_merge_failed

changelogs/unreleased/ce-xanf-move-auto-merge-failed-to-jest.yml

+---
+title: Refactored Karma spec to Jest for mr_widget_auto_merge_failed
+merge_request: 32282
+author: Illya Klymov
+type: other

spec/javascripts/vue_mr_widget/components/states/mr_widget_auto_merge_failed_spec.js → spec/frontend/vue_mr_widget/components/states/mr_widget_auto_merge_failed_spec.js

-import Vue from 'vue';
-import autoMergeFailedComponent from '~/vue_merge_request_widget/components/states/mr_widget_auto_merge_failed.vue';
+import { shallowMount } from '@vue/test-utils';
+import { GlLoadingIcon } from '@gitlab/ui';
+import AutoMergeFailedComponent from '~/vue_merge_request_widget/components/states/mr_widget_auto_merge_failed.vue';
 import eventHub from '~/vue_merge_request_widget/event_hub';
-import mountComponent from 'spec/helpers/vue_mount_component_helper';
 
 describe('MRWidgetAutoMergeFailed', () => {
-  let vm;
+  let wrapper;
   const mergeError = 'This is the merge error';
+  const findButton = () => wrapper.find('button');
+
+  const createComponent = (props = {}) => {
+    wrapper = shallowMount(AutoMergeFailedComponent, {
+      sync: false,
+      propsData: { ...props },
+    });
+  };
 
   beforeEach(() => {
-    const Component = Vue.extend(autoMergeFailedComponent);
-    vm = mountComponent(Component, {
+    createComponent({
       mr: { mergeError },
     });
   });
 
   afterEach(() => {
-    vm.$destroy();
+    wrapper.destroy();
   });
 
   it('renders failed message', () => {
-    expect(vm.$el.textContent).toContain('This merge request failed to be merged automatically');
+    expect(wrapper.text()).toContain('This merge request failed to be merged automatically');
   });
 
   it('renders merge error provided', () => {
-    expect(vm.$el.innerText).toContain(mergeError);
+    expect(wrapper.text()).toContain(mergeError);
   });
 
   it('render refresh button', () => {
-    expect(vm.$el.querySelector('button').textContent.trim()).toEqual('Refresh');
+    expect(findButton().text()).toEqual('Refresh');
   });
 
-  it('emits event and shows loading icon when button is clicked', done => {
-    spyOn(eventHub, '$emit');
-    vm.$el.querySelector('button').click();
+  it('emits event and shows loading icon when button is clicked', () => {
+    jest.spyOn(eventHub, '$emit');
+    findButton().trigger('click');
 
-    expect(eventHub.$emit.calls.argsFor(0)[0]).toEqual('MRWidgetUpdateRequested');
+    expect(eventHub.$emit.mock.calls[0][0]).toBe('MRWidgetUpdateRequested');
 
-    Vue.nextTick(() => {
-      expect(vm.$el.querySelector('button').getAttribute('disabled')).toEqual('disabled');
-      expect(vm.$el.querySelector('button .loading-container span').classList).toContain(
-        'gl-spinner',
-      );
-      done();
+    return wrapper.vm.$nextTick(() => {
+      expect(findButton().attributes('disabled')).toEqual('disabled');
+      expect(
+        findButton()
+          .find(GlLoadingIcon)
+          .exists(),
+      ).toBe(true);
     });
   });
 });