Prepare dropdown_value_spec for bv-upgrade

spec/frontend/vue_shared/components/sidebar/labels_select/dropdown_value_spec.js

-import Vue from 'vue';
-import $ from 'jquery';
+import { mount } from '@vue/test-utils';
 
-import dropdownValueComponent from '~/vue_shared/components/sidebar/labels_select/dropdown_value.vue';
+import DropdownValueComponent from '~/vue_shared/components/sidebar/labels_select/dropdown_value.vue';
+import DropdownValueScopedLabel from '~/vue_shared/components/sidebar/labels_select/dropdown_value_scoped_label.vue';
 
-import mountComponent from 'helpers/vue_mount_component_helper';
 import {
   mockConfig,
   mockLabels,
 } from '../../../../../javascripts/vue_shared/components/sidebar/labels_select/mock_data';
 
+const labelStyles = {
+  textColor: '#FFFFFF',
+  color: '#BADA55',
+};
 const createComponent = (
   labels = mockLabels,
   labelFilterBasePath = mockConfig.labelFilterBasePath,
 ) => {
-  const Component = Vue.extend(dropdownValueComponent);
+  labels.forEach(label => Object.assign(label, labelStyles));
 
-  return mountComponent(Component, {
+  return mount(DropdownValueComponent, {
+    propsData: {
       labels,
       labelFilterBasePath,
       enableScopedLabels: true,
+    },
+    attachToDocument: true,
+    sync: false,
   });
 };
 
@@ -30,7 +37,7 @@ describe('DropdownValueComponent', () => {
   });
 
   afterEach(() => {
-    vm.$destroy();
+    vm.destroy();
   });
 
   describe('computed', () => {
@@ -38,12 +45,12 @@ describe('DropdownValueComponent', () => {
       it('returns true if `labels` prop is empty', () => {
         const vmEmptyLabels = createComponent([]);
 
-        expect(vmEmptyLabels.isEmpty).toBe(true);
-        vmEmptyLabels.$destroy();
+        expect(vmEmptyLabels.classes()).not.toContain('has-labels');
+        vmEmptyLabels.destroy();
       });
 
       it('returns false if `labels` prop is empty', () => {
-        expect(vm.isEmpty).toBe(false);
+        expect(vm.classes()).toContain('has-labels');
       });
     });
   });
@@ -51,88 +58,69 @@ describe('DropdownValueComponent', () => {
   describe('methods', () => {
     describe('labelFilterUrl', () => {
       it('returns URL string starting with labelFilterBasePath and encoded label.title', () => {
-        expect(
-          vm.labelFilterUrl({
-            title: 'Foo bar',
-          }),
-        ).toBe('/gitlab-org/my-project/issues?label_name[]=Foo%20bar');
+        expect(vm.find(DropdownValueScopedLabel).props('labelFilterUrl')).toBe(
+          '/gitlab-org/my-project/issues?label_name[]=Foo%3A%3ABar',
+        );
       });
     });
 
     describe('labelStyle', () => {
       it('returns object with `color` & `backgroundColor` properties from label.textColor & label.color', () => {
-        const label = {
-          textColor: '#FFFFFF',
-          color: '#BADA55',
-        };
-        const styleObj = vm.labelStyle(label);
-
-        expect(styleObj.color).toBe(label.textColor);
-        expect(styleObj.backgroundColor).toBe(label.color);
+        expect(vm.find(DropdownValueScopedLabel).props('labelStyle')).toEqual({
+          color: labelStyles.textColor,
+          backgroundColor: labelStyles.color,
         });
       });
-
-    describe('scopedLabelsDescription', () => {
-      it('returns html for tooltip', () => {
-        const html = vm.scopedLabelsDescription(mockLabels[1]);
-        const $el = $.parseHTML(html);
-
-        expect($el[0]).toHaveClass('scoped-label-tooltip-title');
-        expect($el[2].textContent).toEqual(mockLabels[1].description);
-      });
     });
 
     describe('showScopedLabels', () => {
       it('returns true if the label is scoped label', () => {
-        expect(vm.showScopedLabels(mockLabels[1])).toBe(true);
-      });
-
-      it('returns false when label is a regular label', () => {
-        expect(vm.showScopedLabels(mockLabels[0])).toBe(false);
+        expect(vm.findAll(DropdownValueScopedLabel).length).toEqual(1);
       });
     });
   });
 
   describe('template', () => {
     it('renders component container element with classes `hide-collapsed value issuable-show-labels`', () => {
-      expect(vm.$el.classList.contains('hide-collapsed', 'value', 'issuable-show-labels')).toBe(
-        true,
-      );
+      expect(vm.classes()).toContain('hide-collapsed', 'value', 'issuable-show-labels');
     });
 
     it('render slot content inside component when `labels` prop is empty', () => {
       const vmEmptyLabels = createComponent([]);
 
-      expect(vmEmptyLabels.$el.querySelector('.text-secondary').innerText.trim()).toBe(
-        mockConfig.emptyValueText,
-      );
-      vmEmptyLabels.$destroy();
+      expect(
+        vmEmptyLabels
+          .find('.text-secondary')
+          .text()
+          .trim(),
+      ).toBe(mockConfig.emptyValueText);
+      vmEmptyLabels.destroy();
     });
 
     it('renders label element with filter URL', () => {
-      expect(vm.$el.querySelector('a').getAttribute('href')).toBe(
+      expect(vm.find('a').attributes('href')).toBe(
         '/gitlab-org/my-project/issues?label_name[]=Foo%20Label',
       );
     });
 
     it('renders label element and styles based on label details', () => {
-      const labelEl = vm.$el.querySelector('a span.badge.color-label');
+      const labelEl = vm.find('a span.badge.color-label');
 
-      expect(labelEl).not.toBeNull();
-      expect(labelEl.getAttribute('style')).toBe('background-color: rgb(186, 218, 85);');
-      expect(labelEl.innerText.trim()).toBe(mockLabels[0].title);
+      expect(labelEl.exists()).toBe(true);
+      expect(labelEl.attributes('style')).toContain('background-color: rgb(186, 218, 85);');
+      expect(labelEl.text().trim()).toBe(mockLabels[0].title);
     });
 
     describe('label is of scoped-label type', () => {
       it('renders a scoped-label-wrapper span to incorporate 2 anchors', () => {
-        expect(vm.$el.querySelector('span.scoped-label-wrapper')).not.toBeNull();
+        expect(vm.find('span.scoped-label-wrapper').exists()).toBe(true);
       });
 
       it('renders anchor tag containing question icon', () => {
-        const anchor = vm.$el.querySelector('.scoped-label-wrapper a.scoped-label');
+        const anchor = vm.find('.scoped-label-wrapper a.scoped-label');
 
-        expect(anchor).not.toBeNull();
-        expect(anchor.querySelector('i.fa-question-circle')).not.toBeNull();
+        expect(anchor.exists()).toBe(true);
+        expect(anchor.find('i.fa-question-circle').exists()).toBe(true);
       });
     });
   });