Merge pull request #1245 from winniehell/winniehell-autodestroy

feat: Introduce enableAutoDestroy() helper function

Author: lmiller1990

Diff for: docs/api/README.md

@@ -8,3 +8,4 @@
 !!!include(docs/api/createLocalVue.md)!!!
 !!!include(docs/api/createWrapper.md)!!!
 !!!include(docs/api/config.md)!!!
+!!!include(docs/api/enableAutoDestroy.md)!!!

Diff for: docs/api/enableAutoDestroy.md

@@ -0,0 +1,25 @@
+## enableAutoDestroy(hook)
+
+- **Arguments:**
+
+  - `{Function} hook`
+
+- **Usage:**
+
+`enableAutoDestroy` will destroy all created `Wrapper` instances using the passed hook function (for example [`afterEach`](https://jestjs.io/docs/en/api#aftereachfn-timeout)). After calling the method, you can revert to the default behavior by calling the `resetAutoDestroyState` method.
+
+```js
+import { enableAutoDestroy, mount } from '@vue/test-utils'
+import Foo from './Foo.vue'
+
+// calls wrapper.destroy() after each test
+enableAutoDestroy(afterEach)
+
+describe('Foo', () => {
+  it('renders a div', () => {
+    const wrapper = mount(Foo)
+    expect(wrapper.contains('div')).toBe(true)
+    // no need to call wrapper.destroy() here
+  })
+})
+```

Diff for: packages/test-utils/src/auto-destroy.js

@@ -0,0 +1,37 @@
+// @flow
+
+import { throwError } from 'shared/util'
+import Wrapper from './wrapper'
+
+let isEnabled = false
+const wrapperInstances = []
+
+export function resetAutoDestroyState() {
+  isEnabled = false
+  wrapperInstances.length = 0
+}
+
+export function enableAutoDestroy(hook: (() => void) => void) {
+  if (isEnabled) {
+    throwError('enableAutoDestroy cannot be called more than once')
+  }
+
+  isEnabled = true
+
+  hook(() => {
+    wrapperInstances.forEach((wrapper: Wrapper) => {
+      // skip child wrappers created by wrapper.find()
+      if (wrapper.selector) return
+
+      wrapper.destroy()
+    })
+
+    wrapperInstances.length = 0
+  })
+}
+
+export function trackInstance(wrapper: Wrapper) {
+  if (!isEnabled) return
+
+  wrapperInstances.push(wrapper)
+}

Diff for: packages/test-utils/src/create-wrapper.js

@@ -3,16 +3,22 @@
 import Vue from 'vue'
 import Wrapper from './wrapper'
 import VueWrapper from './vue-wrapper'
+import { trackInstance } from './auto-destroy'
 
 export default function createWrapper(
   node: VNode | Component,
   options: WrapperOptions = {}
 ): VueWrapper | Wrapper {
   const componentInstance = node.child
   if (componentInstance) {
-    return new VueWrapper(componentInstance, options)
+    const wrapper = new VueWrapper(componentInstance, options)
+    trackInstance(wrapper)
+    return wrapper
   }
-  return node instanceof Vue
-    ? new VueWrapper(node, options)
-    : new Wrapper(node, options)
+  const wrapper =
+    node instanceof Vue
+      ? new VueWrapper(node, options)
+      : new Wrapper(node, options)
+  trackInstance(wrapper)
+  return wrapper
 }

Diff for: packages/test-utils/src/index.js

@@ -1,5 +1,6 @@
 import shallowMount from './shallow-mount'
 import mount from './mount'
+import { enableAutoDestroy, resetAutoDestroyState } from './auto-destroy'
 import createLocalVue from './create-local-vue'
 import RouterLinkStub from './components/RouterLinkStub'
 import createWrapper from './create-wrapper'
@@ -20,7 +21,9 @@ export {
   createLocalVue,
   createWrapper,
   config,
+  enableAutoDestroy,
   mount,
+  resetAutoDestroyState,
   shallow,
   shallowMount,
   RouterLinkStub,

Diff for: test/specs/wrapper.spec.js

@@ -1,4 +1,5 @@
 import { describeWithShallowAndMount } from '~resources/utils'
+import { enableAutoDestroy, resetAutoDestroyState } from '~vue/test-utils'
 
 describeWithShallowAndMount('Wrapper', mountingMethod => {
   ;['vnode', 'element', 'vm', 'options'].forEach(property => {
@@ -15,4 +16,41 @@ describeWithShallowAndMount('Wrapper', mountingMethod => {
         .with.property('message', message)
     })
   })
+
+  describe('enableAutoDestroy', () => {
+    const sandbox = sinon.createSandbox()
+
+    beforeEach(() => {
+      resetAutoDestroyState()
+    })
+
+    it('calls the hook function', () => {
+      const hookSpy = sandbox.spy()
+
+      enableAutoDestroy(hookSpy)
+
+      expect(hookSpy).calledOnce
+    })
+
+    it('uses the hook function to destroy wrappers', () => {
+      let hookCallback
+      enableAutoDestroy(callback => {
+        hookCallback = callback
+      })
+      const wrapper = mountingMethod({ template: '<p>con tent</p>' })
+      sandbox.spy(wrapper, 'destroy')
+
+      hookCallback()
+
+      expect(wrapper.destroy).calledOnce
+    })
+
+    it('cannot be called twice', () => {
+      const noop = () => {}
+
+      enableAutoDestroy(noop)
+
+      expect(() => enableAutoDestroy(noop)).to.throw()
+    })
+  })
 })