add tests for resuable dropdown components

spec/javascripts/vue_shared/components/dropdown/dropdown_button_spec.js

+import Vue from 'vue';
+
+import dropdownButtonComponent from '~/vue_shared/components/dropdown/dropdown_button.vue';
+
+import mountComponent from 'spec/helpers/vue_mount_component_helper';
+
+const defaultLabel = 'Select';
+const customLabel = 'Select project';
+
+const createComponent = config => {
+  const Component = Vue.extend(dropdownButtonComponent);
+
+  return mountComponent(Component, config);
+};
+
+describe('DropdownButtonComponent', () => {
+  let vm;
+
+  beforeEach(() => {
+    vm = createComponent();
+  });
+
+  afterEach(() => {
+    vm.$destroy();
+  });
+
+  describe('computed', () => {
+    describe('dropdownToggleText', () => {
+      it('returns default toggle text', () => {
+        expect(vm.toggleText).toBe(defaultLabel);
+      });
+
+      it('returns custom toggle text when provided via props', () => {
+        const vmEmptyLabels = createComponent({ toggleText: customLabel });
+
+        expect(vmEmptyLabels.toggleText).toBe(customLabel);
+        vmEmptyLabels.$destroy();
+      });
+    });
+  });
+
+  describe('template', () => {
+    it('renders component container element of type `button`', () => {
+      expect(vm.$el.nodeName).toBe('BUTTON');
+    });
+
+    it('renders component container element with required data attributes', () => {
+      expect(vm.$el.dataset.abilityName).toBe(vm.abilityName);
+      expect(vm.$el.dataset.fieldName).toBe(vm.fieldName);
+      expect(vm.$el.dataset.issueUpdate).toBe(vm.updatePath);
+      expect(vm.$el.dataset.labels).toBe(vm.labelsPath);
+      expect(vm.$el.dataset.namespacePath).toBe(vm.namespace);
+      expect(vm.$el.dataset.showAny).not.toBeDefined();
+    });
+
+    it('renders dropdown toggle text element', () => {
+      const dropdownToggleTextEl = vm.$el.querySelector('.dropdown-toggle-text');
+      expect(dropdownToggleTextEl).not.toBeNull();
+      expect(dropdownToggleTextEl.innerText.trim()).toBe(defaultLabel);
+    });
+
+    it('renders dropdown button icon', () => {
+      const dropdownIconEl = vm.$el.querySelector('.dropdown-toggle-icon i.fa');
+
+      expect(dropdownIconEl).not.toBeNull();
+      expect(dropdownIconEl.classList.contains('fa-chevron-down')).toBe(true);
+    });
+  });
+});

spec/javascripts/vue_shared/components/dropdown/dropdown_hidden_input_spec.js

+import Vue from 'vue';
+
+import dropdownHiddenInputComponent from '~/vue_shared/components/dropdown/dropdown_hidden_input.vue';
+
+import mountComponent from 'spec/helpers/vue_mount_component_helper';
+
+import { mockLabels } from './mock_data';
+
+const createComponent = (name = 'label_id[]', value = mockLabels[0].id) => {
+  const Component = Vue.extend(dropdownHiddenInputComponent);
+
+  return mountComponent(Component, {
+    name,
+    value,
+  });
+};
+
+describe('DropdownHiddenInputComponent', () => {
+  let vm;
+
+  beforeEach(() => {
+    vm = createComponent();
+  });
+
+  afterEach(() => {
+    vm.$destroy();
+  });
+
+  describe('template', () => {
+    it('renders input element of type `hidden`', () => {
+      expect(vm.$el.nodeName).toBe('INPUT');
+      expect(vm.$el.getAttribute('type')).toBe('hidden');
+      expect(vm.$el.getAttribute('name')).toBe(vm.name);
+      expect(vm.$el.getAttribute('value')).toBe(`${vm.value}`);
+    });
+  });
+});

spec/javascripts/vue_shared/components/dropdown/dropdown_search_input_spec.js

+import Vue from 'vue';
+
+import dropdownSearchInputComponent from '~/vue_shared/components/dropdown/dropdown_search_input.vue';
+
+import mountComponent from 'spec/helpers/vue_mount_component_helper';
+
+const componentConfig = {
+  placeholderText: 'Search something',
+};
+
+const createComponent = (config = componentConfig) => {
+  const Component = Vue.extend(dropdownSearchInputComponent);
+
+  return mountComponent(Component, config);
+};
+
+describe('DropdownSearchInputComponent', () => {
+  let vm;
+
+  beforeEach(() => {
+    vm = createComponent();
+  });
+
+  afterEach(() => {
+    vm.$destroy();
+  });
+
+  describe('template', () => {
+    it('renders input element with type `search`', () => {
+      const inputEl = vm.$el.querySelector('input.dropdown-input-field');
+
+      expect(inputEl).not.toBeNull();
+      expect(inputEl.getAttribute('type')).toBe('search');
+    });
+
+    it('renders search icon element', () => {
+      expect(vm.$el.querySelector('.fa-search.dropdown-input-search')).not.toBeNull();
+    });
+
+    it('renders clear search icon element', () => {
+      expect(
+        vm.$el.querySelector('.fa-times.dropdown-input-clear.js-dropdown-input-clear'),
+      ).not.toBeNull();
+    });
+
+    it('displays custom placeholder text', () => {
+      const inputEl = vm.$el.querySelector('input.dropdown-input-field');
+
+      expect(inputEl.getAttribute('placeholder')).toBe(componentConfig.placeholderText);
+    });
+  });
+});

spec/javascripts/vue_shared/components/dropdown/mock_data.js

+export const mockLabels = [
+  {
+    id: 26,
+    title: 'Foo Label',
+    description: 'Foobar',
+    color: '#BADA55',
+    text_color: '#FFFFFF',
+  },
+];
+
+export default mockLabels;