1 files changed, 117 insertions, 0 deletions
diff --git a/spec/frontend/notes/components/timeline_toggle_spec.js b/spec/frontend/notes/components/timeline_toggle_spec.js
new file mode 100644
index 00000000000..b8df6fc7996
--- /dev/null
+++ b/spec/frontend/notes/components/timeline_toggle_spec.js
@@ -0,0 +1,117 @@
+import { shallowMount, createLocalVue } from '@vue/test-utils';
+import { GlButton } from '@gitlab/ui';
+import Vuex from 'vuex';
+import TimelineToggle, {
+  timelineEnabledTooltip,
+  timelineDisabledTooltip,
+} from '~/notes/components/timeline_toggle.vue';
+import createStore from '~/notes/stores';
+import { ASC, DESC } from '~/notes/constants';
+import { trackToggleTimelineView } from '~/notes/utils';
+import Tracking from '~/tracking';
+
+const localVue = createLocalVue();
+localVue.use(Vuex);
+
+describe('Timeline toggle', () => {
+  let wrapper;
+  let store;
+  const mockEvent = { currentTarget: { blur: jest.fn() } };
+
+  const createComponent = () => {
+    jest.spyOn(store, 'dispatch').mockImplementation();
+    jest.spyOn(Tracking, 'event').mockImplementation();
+
+    wrapper = shallowMount(TimelineToggle, {
+      localVue,
+      store,
+    });
+  };
+
+  const findGlButton = () => wrapper.find(GlButton);
+
+  beforeEach(() => {
+    store = createStore();
+    createComponent();
+  });
+
+  afterEach(() => {
+    if (wrapper) {
+      wrapper.destroy();
+      wrapper = null;
+    }
+    store.dispatch.mockReset();
+    mockEvent.currentTarget.blur.mockReset();
+    Tracking.event.mockReset();
+  });
+
+  describe('ON state', () => {
+    it('should update timeline flag in the store', () => {
+      store.state.isTimelineEnabled = false;
+      findGlButton().vm.$emit('click', mockEvent);
+      expect(store.dispatch).toHaveBeenCalledWith('setTimelineView', true);
+    });
+
+    it('should set sort direction to DESC if not set', () => {
+      store.state.isTimelineEnabled = true;
+      store.state.sortDirection = ASC;
+      findGlButton().vm.$emit('click', mockEvent);
+      expect(store.dispatch).toHaveBeenCalledWith('setDiscussionSortDirection', {
+        direction: DESC,
+        persist: false,
+      });
+    });
+
+    it('should set correct UI state', async () => {
+      store.state.isTimelineEnabled = true;
+      findGlButton().vm.$emit('click', mockEvent);
+      await wrapper.vm.$nextTick();
+      expect(findGlButton().attributes('title')).toBe(timelineEnabledTooltip);
+      expect(findGlButton().attributes('selected')).toBe('true');
+      expect(mockEvent.currentTarget.blur).toHaveBeenCalled();
+    });
+
+    it('should track Snowplow event', async () => {
+      store.state.isTimelineEnabled = true;
+      await wrapper.vm.$nextTick();
+
+      findGlButton().trigger('click');
+
+      const { category, action, label, property, value } = trackToggleTimelineView(true);
+      expect(Tracking.event).toHaveBeenCalledWith(category, action, { label, property, value });
+    });
+  });
+
+  describe('OFF state', () => {
+    it('should update timeline flag in the store', () => {
+      store.state.isTimelineEnabled = true;
+      findGlButton().vm.$emit('click', mockEvent);
+      expect(store.dispatch).toHaveBeenCalledWith('setTimelineView', false);
+    });
+
+    it('should NOT update sort direction', () => {
+      store.state.isTimelineEnabled = false;
+      findGlButton().vm.$emit('click', mockEvent);
+      expect(store.dispatch).not.toHaveBeenCalledWith();
+    });
+
+    it('should set correct UI state', async () => {
+      store.state.isTimelineEnabled = false;
+      findGlButton().vm.$emit('click', mockEvent);
+      await wrapper.vm.$nextTick();
+      expect(findGlButton().attributes('title')).toBe(timelineDisabledTooltip);
+      expect(findGlButton().attributes('selected')).toBe(undefined);
+      expect(mockEvent.currentTarget.blur).toHaveBeenCalled();
+    });
+
+    it('should track Snowplow event', async () => {
+      store.state.isTimelineEnabled = false;
+      await wrapper.vm.$nextTick();
+
+      findGlButton().trigger('click');
+
+      const { category, action, label, property, value } = trackToggleTimelineView(false);
+      expect(Tracking.event).toHaveBeenCalledWith(category, action, { label, property, value });
+    });
+  });
+});