Merge branch 'kp-label-select-vue' into 'master'

Port Labels Select dropdown to Vue

See merge request gitlab-org/gitlab-ce!17411

17 files changed, 666 insertions, 6 deletions

diff --git a/spec/javascripts/boards/board_card_spec.js b/spec/javascripts/boards/board_card_spec.js
index 80a598e63bd..13d607a06d2 100644
--- a/spec/javascripts/boards/board_card_spec.js
+++ b/spec/javascripts/boards/board_card_spec.js
@@ -9,8 +9,8 @@ import axios from '~/lib/utils/axios_utils';
 import '~/boards/models/assignee';
 
 import eventHub from '~/boards/eventhub';
+import '~/vue_shared/models/label';
 import '~/boards/models/list';
-import '~/boards/models/label';
 import '~/boards/stores/boards_store';
 import boardCard from '~/boards/components/board_card.vue';
 import { listObj, boardsMockInterceptor, mockBoardService } from './mock_data';
diff --git a/spec/javascripts/boards/boards_store_spec.js b/spec/javascripts/boards/boards_store_spec.js
index 8411f4dd8a6..0cf9e4c9ba1 100644
--- a/spec/javascripts/boards/boards_store_spec.js
+++ b/spec/javascripts/boards/boards_store_spec.js
@@ -7,8 +7,8 @@ import MockAdapter from 'axios-mock-adapter';
 import axios from '~/lib/utils/axios_utils';
 import Cookies from 'js-cookie';
 
+import '~/vue_shared/models/label';
 import '~/boards/models/issue';
-import '~/boards/models/label';
 import '~/boards/models/list';
 import '~/boards/models/assignee';
 import '~/boards/services/board_service';
diff --git a/spec/javascripts/boards/issue_card_spec.js b/spec/javascripts/boards/issue_card_spec.js
index 278155c585e..37088a6421c 100644
--- a/spec/javascripts/boards/issue_card_spec.js
+++ b/spec/javascripts/boards/issue_card_spec.js
@@ -4,8 +4,8 @@
 
 import Vue from 'vue';
 
+import '~/vue_shared/models/label';
 import '~/boards/models/issue';
-import '~/boards/models/label';
 import '~/boards/models/list';
 import '~/boards/models/assignee';
 import '~/boards/stores/boards_store';
diff --git a/spec/javascripts/boards/issue_spec.js b/spec/javascripts/boards/issue_spec.js
index dbbe14fe3e0..4a11131b55c 100644
--- a/spec/javascripts/boards/issue_spec.js
+++ b/spec/javascripts/boards/issue_spec.js
@@ -3,8 +3,8 @@
 /* global ListIssue */
 
 import Vue from 'vue';
+import '~/vue_shared/models/label';
 import '~/boards/models/issue';
-import '~/boards/models/label';
 import '~/boards/models/list';
 import '~/boards/models/assignee';
 import '~/boards/services/board_service';
diff --git a/spec/javascripts/boards/list_spec.js b/spec/javascripts/boards/list_spec.js
index 34964b20b05..d9a1d692949 100644
--- a/spec/javascripts/boards/list_spec.js
+++ b/spec/javascripts/boards/list_spec.js
@@ -6,8 +6,8 @@
 import MockAdapter from 'axios-mock-adapter';
 import axios from '~/lib/utils/axios_utils';
 import _ from 'underscore';
+import '~/vue_shared/models/label';
 import '~/boards/models/issue';
-import '~/boards/models/label';
 import '~/boards/models/list';
 import '~/boards/models/assignee';
 import '~/boards/services/board_service';
diff --git a/spec/javascripts/boards/modal_store_spec.js b/spec/javascripts/boards/modal_store_spec.js
index 7eecb58a4c3..e9d77f035e3 100644
--- a/spec/javascripts/boards/modal_store_spec.js
+++ b/spec/javascripts/boards/modal_store_spec.js
@@ -1,7 +1,7 @@
 /* global ListIssue */
 
+import '~/vue_shared/models/label';
 import '~/boards/models/issue';
-import '~/boards/models/label';
 import '~/boards/models/list';
 import '~/boards/models/assignee';
 import '~/boards/stores/modal_store';
diff --git a/spec/javascripts/vue_shared/components/sidebar/labels_select/base_spec.js b/spec/javascripts/vue_shared/components/sidebar/labels_select/base_spec.js
new file mode 100644
index 00000000000..67056793a20
--- /dev/null
+++ b/spec/javascripts/vue_shared/components/sidebar/labels_select/base_spec.js
@@ -0,0 +1,81 @@
+import Vue from 'vue';
+
+import LabelsSelect from '~/labels_select';
+import baseComponent from '~/vue_shared/components/sidebar/labels_select/base.vue';
+
+import { mockConfig, mockLabels } from './mock_data';
+
+import mountComponent from '../../../../helpers/vue_mount_component_helper';
+
+const createComponent = (config = mockConfig) => {
+  const Component = Vue.extend(baseComponent);
+
+  return mountComponent(Component, config);
+};
+
+describe('BaseComponent', () => {
+  let vm;
+
+  beforeEach(() => {
+    vm = createComponent();
+  });
+
+  afterEach(() => {
+    vm.$destroy();
+  });
+
+  describe('computed', () => {
+    describe('hiddenInputName', () => {
+      it('returns correct string when showCreate prop is `true`', () => {
+        expect(vm.hiddenInputName).toBe('issue[label_names][]');
+      });
+
+      it('returns correct string when showCreate prop is `false`', () => {
+        const mockConfigNonEditable = Object.assign({}, mockConfig, { showCreate: false });
+        const vmNonEditable = createComponent(mockConfigNonEditable);
+        expect(vmNonEditable.hiddenInputName).toBe('label_id[]');
+        vmNonEditable.$destroy();
+      });
+    });
+  });
+
+  describe('methods', () => {
+    describe('handleClick', () => {
+      it('emits onLabelClick event with label and list of labels as params', () => {
+        spyOn(vm, '$emit');
+        vm.handleClick(mockLabels[0]);
+        expect(vm.$emit).toHaveBeenCalledWith('onLabelClick', mockLabels[0]);
+      });
+    });
+  });
+
+  describe('mounted', () => {
+    it('creates LabelsSelect object and assigns it to `labelsDropdon` as prop', () => {
+      expect(vm.labelsDropdown instanceof LabelsSelect).toBe(true);
+    });
+  });
+
+  describe('template', () => {
+    it('renders component container element with classes `block labels`', () => {
+      expect(vm.$el.classList.contains('block')).toBe(true);
+      expect(vm.$el.classList.contains('labels')).toBe(true);
+    });
+
+    it('renders `.selectbox` element', () => {
+      expect(vm.$el.querySelector('.selectbox')).not.toBeNull();
+      expect(vm.$el.querySelector('.selectbox').getAttribute('style')).toBe('display: none;');
+    });
+
+    it('renders `.dropdown` element', () => {
+      expect(vm.$el.querySelector('.dropdown')).not.toBeNull();
+    });
+
+    it('renders `.dropdown-menu` element', () => {
+      const dropdownMenuEl = vm.$el.querySelector('.dropdown-menu');
+      expect(dropdownMenuEl).not.toBeNull();
+      expect(dropdownMenuEl.querySelector('.dropdown-page-one')).not.toBeNull();
+      expect(dropdownMenuEl.querySelector('.dropdown-content')).not.toBeNull();
+      expect(dropdownMenuEl.querySelector('.dropdown-loading')).not.toBeNull();
+    });
+  });
+});
diff --git a/spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_button_spec.js b/spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_button_spec.js
new file mode 100644
index 00000000000..ec63ac306d0
--- /dev/null
+++ b/spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_button_spec.js
@@ -0,0 +1,82 @@
+import Vue from 'vue';
+
+import dropdownButtonComponent from '~/vue_shared/components/sidebar/labels_select/dropdown_button.vue';
+
+import { mockConfig, mockLabels } from './mock_data';
+
+import mountComponent from '../../../../helpers/vue_mount_component_helper';
+
+const componentConfig = Object.assign({}, mockConfig, {
+  fieldName: 'label_id[]',
+  labels: mockLabels,
+  showExtraOptions: false,
+});
+
+const createComponent = (config = componentConfig) => {
+  const Component = Vue.extend(dropdownButtonComponent);
+
+  return mountComponent(Component, config);
+};
+
+describe('DropdownButtonComponent', () => {
+  let vm;
+
+  beforeEach(() => {
+    vm = createComponent();
+  });
+
+  afterEach(() => {
+    vm.$destroy();
+  });
+
+  describe('computed', () => {
+    describe('dropdownToggleText', () => {
+      it('returns text as `Label` when `labels` prop is empty array', () => {
+        const mockEmptyLabels = Object.assign({}, componentConfig, { labels: [] });
+        const vmEmptyLabels = createComponent(mockEmptyLabels);
+        expect(vmEmptyLabels.dropdownToggleText).toBe('Label');
+        vmEmptyLabels.$destroy();
+      });
+
+      it('returns first label name with remaining label count when `labels` prop has more than one item', () => {
+        const mockMoreLabels = Object.assign({}, componentConfig, {
+          labels: mockLabels.concat(mockLabels),
+        });
+        const vmMoreLabels = createComponent(mockMoreLabels);
+        expect(vmMoreLabels.dropdownToggleText).toBe('Foo Label +1 more');
+        vmMoreLabels.$destroy();
+      });
+
+      it('returns first label name when `labels` prop has only one item present', () => {
+        expect(vm.dropdownToggleText).toBe('Foo Label');
+      });
+    });
+  });
+
+  describe('template', () => {
+    it('renders component container element of type `button`', () => {
+      expect(vm.$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.$el.querySelector('.dropdown-toggle-text');
+      expect(dropdownToggleTextEl).not.toBeNull();
+      expect(dropdownToggleTextEl.innerText.trim()).toBe('Foo Label');
+    });
+
+    it('renders dropdown button icon', () => {
+      const dropdownIconEl = vm.$el.querySelector('i.fa');
+      expect(dropdownIconEl).not.toBeNull();
+      expect(dropdownIconEl.classList.contains('fa-chevron-down')).toBe(true);
+    });
+  });
+});
diff --git a/spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_create_label_spec.js b/spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_create_label_spec.js
new file mode 100644
index 00000000000..f07aefb2f87
--- /dev/null
+++ b/spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_create_label_spec.js
@@ -0,0 +1,84 @@
+import Vue from 'vue';
+
+import dropdownCreateLabelComponent from '~/vue_shared/components/sidebar/labels_select/dropdown_create_label.vue';
+
+import { mockSuggestedColors } from './mock_data';
+
+import mountComponent from '../../../../helpers/vue_mount_component_helper';
+
+const createComponent = () => {
+  const Component = Vue.extend(dropdownCreateLabelComponent);
+
+  return mountComponent(Component);
+};
+
+describe('DropdownCreateLabelComponent', () => {
+  let vm;
+
+  beforeEach(() => {
+    gon.suggested_label_colors = mockSuggestedColors;
+    vm = createComponent();
+  });
+
+  afterEach(() => {
+    vm.$destroy();
+  });
+
+  describe('created', () => {
+    it('initializes `suggestedColors` prop on component from `gon.suggested_color_labels` object', () => {
+      expect(vm.suggestedColors.length).toBe(mockSuggestedColors.length);
+    });
+  });
+
+  describe('template', () => {
+    it('renders component container element with classes `dropdown-page-two dropdown-new-label`', () => {
+      expect(vm.$el.classList.contains('dropdown-page-two', 'dropdown-new-label')).toBe(true);
+    });
+
+    it('renders `Go back` button on component header', () => {
+      const backButtonEl = vm.$el.querySelector('.dropdown-title button.dropdown-title-button.dropdown-menu-back');
+      expect(backButtonEl).not.toBe(null);
+      expect(backButtonEl.querySelector('.fa-arrow-left')).not.toBe(null);
+    });
+
+    it('renders component header element', () => {
+      const headerEl = vm.$el.querySelector('.dropdown-title');
+      expect(headerEl.innerText.trim()).toContain('Create new label');
+    });
+
+    it('renders `Close` button on component header', () => {
+      const closeButtonEl = vm.$el.querySelector('.dropdown-title button.dropdown-title-button.dropdown-menu-close');
+      expect(closeButtonEl).not.toBe(null);
+      expect(closeButtonEl.querySelector('.fa-times.dropdown-menu-close-icon')).not.toBe(null);
+    });
+
+    it('renders `Name new label` input element', () => {
+      expect(vm.$el.querySelector('.dropdown-labels-error.js-label-error')).not.toBe(null);
+      expect(vm.$el.querySelector('input#new_label_name.default-dropdown-input')).not.toBe(null);
+    });
+
+    it('renders suggested colors list elements', () => {
+      const colorsListContainerEl = vm.$el.querySelector('.suggest-colors.suggest-colors-dropdown');
+      expect(colorsListContainerEl).not.toBe(null);
+      expect(colorsListContainerEl.querySelectorAll('a').length).toBe(mockSuggestedColors.length);
+
+      const colorItemEl = colorsListContainerEl.querySelectorAll('a')[0];
+      expect(colorItemEl.dataset.color).toBe(vm.suggestedColors[0]);
+      expect(colorItemEl.getAttribute('style')).toBe('background-color: rgb(0, 51, 204);');
+    });
+
+    it('renders color input element', () => {
+      expect(vm.$el.querySelector('.dropdown-label-color-input')).not.toBe(null);
+      expect(vm.$el.querySelector('.dropdown-label-color-preview.js-dropdown-label-color-preview')).not.toBe(null);
+      expect(vm.$el.querySelector('input#new_label_color.default-dropdown-input')).not.toBe(null);
+    });
+
+    it('renders component action buttons', () => {
+      const createBtnEl = vm.$el.querySelector('button.js-new-label-btn');
+      const cancelBtnEl = vm.$el.querySelector('button.js-cancel-label-btn');
+      expect(createBtnEl).not.toBe(null);
+      expect(createBtnEl.innerText.trim()).toBe('Create');
+      expect(cancelBtnEl.innerText.trim()).toBe('Cancel');
+    });
+  });
+});
diff --git a/spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_footer_spec.js b/spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_footer_spec.js
new file mode 100644
index 00000000000..809e0327b1c
--- /dev/null
+++ b/spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_footer_spec.js
@@ -0,0 +1,42 @@
+import Vue from 'vue';
+
+import dropdownFooterComponent from '~/vue_shared/components/sidebar/labels_select/dropdown_footer.vue';
+
+import { mockConfig } from './mock_data';
+
+import mountComponent from '../../../../helpers/vue_mount_component_helper';
+
+const createComponent = (labelsWebUrl = mockConfig.labelsWebUrl) => {
+  const Component = Vue.extend(dropdownFooterComponent);
+
+  return mountComponent(Component, {
+    labelsWebUrl,
+  });
+};
+
+describe('DropdownFooterComponent', () => {
+  let vm;
+
+  beforeEach(() => {
+    vm = createComponent();
+  });
+
+  afterEach(() => {
+    vm.$destroy();
+  });
+
+  describe('template', () => {
+    it('renders `Create new label` link element', () => {
+      const createLabelEl = vm.$el.querySelector('.dropdown-footer-list .dropdown-toggle-page');
+      expect(createLabelEl).not.toBeNull();
+      expect(createLabelEl.innerText.trim()).toBe('Create new label');
+    });
+
+    it('renders `Manage labels` link element', () => {
+      const manageLabelsEl = vm.$el.querySelector('.dropdown-footer-list .dropdown-external-link');
+      expect(manageLabelsEl).not.toBeNull();
+      expect(manageLabelsEl.getAttribute('href')).toBe(vm.labelsWebUrl);
+      expect(manageLabelsEl.innerText.trim()).toBe('Manage labels');
+    });
+  });
+});
diff --git a/spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_header_spec.js b/spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_header_spec.js
new file mode 100644
index 00000000000..325fa47c957
--- /dev/null
+++ b/spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_header_spec.js
@@ -0,0 +1,36 @@
+import Vue from 'vue';
+
+import dropdownHeaderComponent from '~/vue_shared/components/sidebar/labels_select/dropdown_header.vue';
+
+import mountComponent from '../../../../helpers/vue_mount_component_helper';
+
+const createComponent = () => {
+  const Component = Vue.extend(dropdownHeaderComponent);
+
+  return mountComponent(Component);
+};
+
+describe('DropdownHeaderComponent', () => {
+  let vm;
+
+  beforeEach(() => {
+    vm = createComponent();
+  });
+
+  afterEach(() => {
+    vm.$destroy();
+  });
+
+  describe('template', () => {
+    it('renders header text element', () => {
+      const headerEl = vm.$el.querySelector('.dropdown-title span');
+      expect(headerEl.innerText.trim()).toBe('Assign labels');
+    });
+
+    it('renders `Close` button element', () => {
+      const closeBtnEl = vm.$el.querySelector('.dropdown-title button.dropdown-title-button.dropdown-menu-close');
+      expect(closeBtnEl).not.toBeNull();
+      expect(closeBtnEl.querySelector('.fa-times.dropdown-menu-close-icon')).not.toBeNull();
+    });
+  });
+});
diff --git a/spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_hidden_input_spec.js b/spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_hidden_input_spec.js
new file mode 100644
index 00000000000..703b87498c7
--- /dev/null
+++ b/spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_hidden_input_spec.js
@@ -0,0 +1,37 @@
+import Vue from 'vue';
+
+import dropdownHiddenInputComponent from '~/vue_shared/components/sidebar/labels_select/dropdown_hidden_input.vue';
+
+import { mockLabels } from './mock_data';
+
+import mountComponent from '../../../../helpers/vue_mount_component_helper';
+
+const createComponent = (name = 'label_id[]', label = mockLabels[0]) => {
+  const Component = Vue.extend(dropdownHiddenInputComponent);
+
+  return mountComponent(Component, {
+    name,
+    label,
+  });
+};
+
+describe('DropdownHiddenInputComponent', () => {
+  let vm;
+
+  beforeEach(() => {
+    vm = createComponent();
+  });
+
+  afterEach(() => {
+    vm.$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(`${vm.label.id}`);
+    });
+  });
+});
diff --git a/spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_search_input_spec.js b/spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_search_input_spec.js
new file mode 100644
index 00000000000..69e11d966c2
--- /dev/null
+++ b/spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_search_input_spec.js
@@ -0,0 +1,39 @@
+import Vue from 'vue';
+
+import dropdownSearchInputComponent from '~/vue_shared/components/sidebar/labels_select/dropdown_search_input.vue';
+
+import mountComponent from '../../../../helpers/vue_mount_component_helper';
+
+const createComponent = () => {
+  const Component = Vue.extend(dropdownSearchInputComponent);
+
+  return mountComponent(Component);
+};
+
+describe('DropdownSearchInputComponent', () => {
+  let vm;
+
+  beforeEach(() => {
+    vm = createComponent();
+  });
+
+  afterEach(() => {
+    vm.$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.$el.querySelector('.fa-times.dropdown-input-clear.js-dropdown-input-clear')).not.toBeNull();
+    });
+  });
+});
diff --git a/spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_title_spec.js b/spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_title_spec.js
new file mode 100644
index 00000000000..c3580933072
--- /dev/null
+++ b/spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_title_spec.js
@@ -0,0 +1,42 @@
+import Vue from 'vue';
+
+import dropdownTitleComponent from '~/vue_shared/components/sidebar/labels_select/dropdown_title.vue';
+
+import mountComponent from '../../../../helpers/vue_mount_component_helper';
+
+const createComponent = (canEdit = true) => {
+  const Component = Vue.extend(dropdownTitleComponent);
+
+  return mountComponent(Component, {
+    canEdit,
+  });
+};
+
+describe('DropdownTitleComponent', () => {
+  let vm;
+
+  beforeEach(() => {
+    vm = createComponent();
+  });
+
+  afterEach(() => {
+    vm.$destroy();
+  });
+
+  describe('template', () => {
+    it('renders title text', () => {
+      expect(vm.$el.classList.contains('title', 'hide-collapsed')).toBe(true);
+      expect(vm.$el.innerText.trim()).toContain('Labels');
+    });
+
+    it('renders spinner icon element', () => {
+      expect(vm.$el.querySelector('.fa-spinner.fa-spin.block-loading')).not.toBeNull();
+    });
+
+    it('renders `Edit` button element', () => {
+      const editBtnEl = vm.$el.querySelector('button.edit-link.js-sidebar-dropdown-toggle');
+      expect(editBtnEl).not.toBeNull();
+      expect(editBtnEl.innerText.trim()).toBe('Edit');
+    });
+  });
+});
diff --git a/spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_value_collapsed_spec.js b/spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_value_collapsed_spec.js
new file mode 100644
index 00000000000..93b42795bea
--- /dev/null
+++ b/spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_value_collapsed_spec.js
@@ -0,0 +1,74 @@
+import Vue from 'vue';
+
+import dropdownValueCollapsedComponent from '~/vue_shared/components/sidebar/labels_select/dropdown_value_collapsed.vue';
+
+import { mockLabels } from './mock_data';
+
+import mountComponent from '../../../../helpers/vue_mount_component_helper';
+
+const createComponent = (labels = mockLabels) => {
+  const Component = Vue.extend(dropdownValueCollapsedComponent);
+
+  return mountComponent(Component, {
+    labels,
+  });
+};
+
+describe('DropdownValueCollapsedComponent', () => {
+  let vm;
+
+  beforeEach(() => {
+    vm = createComponent();
+  });
+
+  afterEach(() => {
+    vm.$destroy();
+  });
+
+  describe('computed', () => {
+    describe('labelsList', () => {
+      it('returns empty text when `labels` prop is empty array', () => {
+        const vmEmptyLabels = createComponent([]);
+        expect(vmEmptyLabels.labelsList).toBe('');
+        vmEmptyLabels.$destroy();
+      });
+
+      it('returns labels names separated by coma when `labels` prop has more than one item', () => {
+        const vmMoreLabels = createComponent(mockLabels.concat(mockLabels));
+        expect(vmMoreLabels.labelsList).toBe('Foo Label, Foo Label');
+        vmMoreLabels.$destroy();
+      });
+
+      it('returns labels names separated by coma with remaining labels count and `and more` phrase when `labels` prop has more than five items', () => {
+        const mockMoreLabels = Object.assign([], mockLabels);
+        for (let i = 0; i < 6; i += 1) {
+          mockMoreLabels.unshift(mockLabels[0]);
+        }
+
+        const vmMoreLabels = createComponent(mockMoreLabels);
+        expect(vmMoreLabels.labelsList).toBe('Foo Label, Foo Label, Foo Label, Foo Label, Foo Label, and 2 more');
+        vmMoreLabels.$destroy();
+      });
+
+      it('returns first label name when `labels` prop has only one item present', () => {
+        expect(vm.labelsList).toBe('Foo Label');
+      });
+    });
+  });
+
+  describe('template', () => {
+    it('renders component container element with tooltip`', () => {
+      expect(vm.$el.dataset.placement).toBe('left');
+      expect(vm.$el.dataset.container).toBe('body');
+      expect(vm.$el.dataset.originalTitle).toBe(vm.labelsList);
+    });
+
+    it('renders tags icon element', () => {
+      expect(vm.$el.querySelector('.fa-tags')).not.toBeNull();
+    });
+
+    it('renders labels count', () => {
+      expect(vm.$el.querySelector('span').innerText.trim()).toBe(`${vm.labels.length}`);
+    });
+  });
+});
diff --git a/spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_value_spec.js b/spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_value_spec.js
new file mode 100644
index 00000000000..66e0957b431
--- /dev/null
+++ b/spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_value_spec.js
@@ -0,0 +1,94 @@
+import Vue from 'vue';
+
+import dropdownValueComponent from '~/vue_shared/components/sidebar/labels_select/dropdown_value.vue';
+
+import { mockConfig, mockLabels } from './mock_data';
+
+import mountComponent from '../../../../helpers/vue_mount_component_helper';
+
+const createComponent = (
+  labels = mockLabels,
+  labelFilterBasePath = mockConfig.labelFilterBasePath,
+) => {
+  const Component = Vue.extend(dropdownValueComponent);
+
+  return mountComponent(Component, {
+    labels,
+    labelFilterBasePath,
+  });
+};
+
+describe('DropdownValueComponent', () => {
+  let vm;
+
+  beforeEach(() => {
+    vm = createComponent();
+  });
+
+  afterEach(() => {
+    vm.$destroy();
+  });
+
+  describe('computed', () => {
+    describe('isEmpty', () => {
+      it('returns true if `labels` prop is empty', () => {
+        const vmEmptyLabels = createComponent([]);
+        expect(vmEmptyLabels.isEmpty).toBe(true);
+        vmEmptyLabels.$destroy();
+      });
+
+      it('returns false if `labels` prop is empty', () => {
+        expect(vm.isEmpty).toBe(false);
+      });
+    });
+  });
+
+  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');
+      });
+    });
+
+    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);
+      });
+    });
+  });
+
+  describe('template', () => {
+    it('renders component container element with classes `hide-collapsed value issuable-show-labels`', () => {
+      expect(vm.$el.classList.contains('hide-collapsed', 'value', 'issuable-show-labels')).toBe(true);
+    });
+
+    it('render slot content inside component when `labels` prop is empty', () => {
+      const vmEmptyLabels = createComponent([]);
+      expect(vmEmptyLabels.$el.querySelector('.text-secondary').innerText.trim()).toBe(mockConfig.emptyValueText);
+      vmEmptyLabels.$destroy();
+    });
+
+    it('renders label element with filter URL', () => {
+      expect(vm.$el.querySelector('a').getAttribute('href')).toBe('/gitlab-org/my-project/issues?label_name[]=Foo%20Label');
+    });
+
+    it('renders label element with tooltip and styles based on label details', () => {
+      const labelEl = vm.$el.querySelector('a span.label.color-label');
+      expect(labelEl).not.toBeNull();
+      expect(labelEl.dataset.placement).toBe('bottom');
+      expect(labelEl.dataset.container).toBe('body');
+      expect(labelEl.dataset.originalTitle).toBe(mockLabels[0].description);
+      expect(labelEl.getAttribute('style')).toBe('background-color: rgb(186, 218, 85);');
+      expect(labelEl.innerText.trim()).toBe(mockLabels[0].title);
+    });
+  });
+});
diff --git a/spec/javascripts/vue_shared/components/sidebar/labels_select/mock_data.js b/spec/javascripts/vue_shared/components/sidebar/labels_select/mock_data.js
new file mode 100644
index 00000000000..e9008c29b22
--- /dev/null
+++ b/spec/javascripts/vue_shared/components/sidebar/labels_select/mock_data.js
@@ -0,0 +1,49 @@
+export const mockLabels = [
+  {
+    id: 26,
+    title: 'Foo Label',
+    description: 'Foobar',
+    color: '#BADA55',
+    text_color: '#FFFFFF',
+  },
+];
+
+export const mockSuggestedColors = [
+  '#0033CC',
+  '#428BCA',
+  '#44AD8E',
+  '#A8D695',
+  '#5CB85C',
+  '#69D100',
+  '#004E00',
+  '#34495E',
+  '#7F8C8D',
+  '#A295D6',
+  '#5843AD',
+  '#8E44AD',
+  '#FFECDB',
+  '#AD4363',
+  '#D10069',
+  '#CC0033',
+  '#FF0000',
+  '#D9534F',
+  '#D1D100',
+  '#F0AD4E',
+  '#AD8D43',
+];
+
+export const mockConfig = {
+  showCreate: true,
+  abilityName: 'issue',
+  context: {
+    labels: mockLabels,
+  },
+  namespace: 'gitlab-org',
+  updatePath: '/gitlab-org/my-project/issue/1',
+  labelsPath: '/gitlab-org/my-project/labels.json',
+  labelsWebUrl: '/gitlab-org/my-project/labels',
+  labelFilterBasePath: '/gitlab-org/my-project/issues',
+  canEdit: true,
+  suggestedColors: mockSuggestedColors,
+  emptyValueText: 'None',
+};