feat: add pause/resume methods to pause updates

test/plugin-browser.test.js

@@ -1,5 +1,9 @@
-import { mount, defaultOptions, VueMetaBrowserPlugin, loadVueMetaPlugin } from './utils'
+import triggerUpdate from '../src/client/triggerUpdate'
+import batchUpdate from '../src/client/batchUpdate'
+import { mount, defaultOptions, vmTick, VueMetaBrowserPlugin, loadVueMetaPlugin } from './utils'
 
+jest.mock('../src/client/triggerUpdate')
+jest.mock('../src/client/batchUpdate')
 jest.mock('../package.json', () => ({
   version: 'test-version'
 }))
@@ -7,6 +11,7 @@ jest.mock('../package.json', () => ({
 describe('plugin', () => {
   let Vue
 
+  beforeEach(() => jest.clearAllMocks())
   beforeAll(() => (Vue = loadVueMetaPlugin(true)))
 
   test('is loaded', () => {
@@ -35,4 +40,64 @@ describe('plugin', () => {
   test('plugin sets package version', () => {
     expect(VueMetaBrowserPlugin.version).toBe('test-version')
   })
+
+  test('updates can be paused and resumed', async () => {
+    const _triggerUpdate = jest.requireActual('../src/client/triggerUpdate').default
+    const triggerUpdateSpy = triggerUpdate.mockImplementation(_triggerUpdate)
+
+    const Component = Vue.component('test-component', {
+      metaInfo() {
+        return {
+          title: this.title
+        }
+      },
+      props: {
+        title: {
+          type: String,
+          default: ''
+        }
+      },
+      template: '<div>Test</div>'
+    })
+
+    let title = 'first title'
+    const wrapper = mount(Component, {
+      localVue: Vue,
+      propsData: {
+        title
+      }
+    })
+
+    // no batchUpdate on initialization
+    expect(wrapper.vm.$root._vueMetaInitialized).toBe(false)
+    expect(wrapper.vm.$root._vueMetaPaused).toBeFalsy()
+    expect(triggerUpdateSpy).toHaveBeenCalledTimes(1)
+    expect(batchUpdate).not.toHaveBeenCalled()
+    jest.clearAllMocks()
+    await vmTick(wrapper.vm)
+
+    title = 'second title'
+    wrapper.setProps({ title })
+
+    // batchUpdate on normal update
+    expect(wrapper.vm.$root._vueMetaInitialized).toBe(true)
+    expect(wrapper.vm.$root._vueMetaPaused).toBeFalsy()
+    expect(triggerUpdateSpy).toHaveBeenCalledTimes(1)
+    expect(batchUpdate).toHaveBeenCalledTimes(1)
+    jest.clearAllMocks()
+
+    wrapper.vm.$meta().pause()
+    title = 'third title'
+    wrapper.setProps({ title })
+
+    // no batchUpdate when paused
+    expect(wrapper.vm.$root._vueMetaInitialized).toBe(true)
+    expect(wrapper.vm.$root._vueMetaPaused).toBe(true)
+    expect(triggerUpdateSpy).toHaveBeenCalledTimes(1)
+    expect(batchUpdate).not.toHaveBeenCalled()
+    jest.clearAllMocks()
+
+    const metaInfo = wrapper.vm.$meta().resume()
+    expect(metaInfo.title).toBe(title)
+  })
 })