fix: wrap extended child components (#840)

Author: eddyerburgh

Diff for: packages/create-instance/add-mocks.js

@@ -3,7 +3,7 @@ import $$Vue from 'vue'
 import { warn } from 'shared/util'
 
 export default function addMocks (
-  mockedProperties: Object,
+  mockedProperties: Object = {},
   Vue: Component
 ): void {
   Object.keys(mockedProperties).forEach(key => {

Diff for: packages/create-instance/add-stubs.js

@@ -0,0 +1,22 @@
+import { createComponentStubs } from 'shared/stub-components'
+
+export function addStubs (component, stubs, _Vue) {
+  const stubComponents = createComponentStubs(
+    component.components,
+    stubs
+  )
+
+  function addStubComponentsMixin () {
+    Object.assign(
+      this.$options.components,
+      stubComponents
+    )
+  }
+
+  _Vue.mixin({
+    beforeMount: addStubComponentsMixin,
+    // beforeCreate is for components created in node, which
+    // never mount
+    beforeCreate: addStubComponentsMixin
+  })
+}

Diff for: packages/create-instance/create-instance.js

@@ -3,15 +3,16 @@
 import { createSlotVNodes } from './create-slot-vnodes'
 import addMocks from './add-mocks'
 import { addEventLogger } from './log-events'
-import { createComponentStubs } from 'shared/stub-components'
-import { throwError, warn, vueVersion } from 'shared/util'
+import { addStubs } from './add-stubs'
+import { throwError, vueVersion } from 'shared/util'
 import { compileTemplate } from 'shared/compile-template'
 import { isRequiredComponent } from 'shared/validators'
 import extractInstanceOptions from './extract-instance-options'
 import createFunctionalComponent from './create-functional-component'
 import { componentNeedsCompiling, isPlainObject } from 'shared/validators'
 import { validateSlots } from './validate-slots'
 import createScopedSlots from './create-scoped-slots'
+import { extendExtendedComponents } from './extend-extended-components'
 
 function compileTemplateForSlots (slots: Object): void {
   Object.keys(slots).forEach(key => {
@@ -33,21 +34,14 @@ export default function createInstance (
   // Remove cached constructor
   delete component._Ctor
 
-  // mounting options are vue-test-utils specific
-  //
   // instance options are options that are passed to the
   // root instance when it's instantiated
-  //
-  // component options are the root components options
-  const componentOptions = typeof component === 'function'
-    ? component.extendOptions
-    : component
-
   const instanceOptions = extractInstanceOptions(options)
 
-  if (options.mocks) {
-    addMocks(options.mocks, _Vue)
-  }
+  addEventLogger(_Vue)
+  addMocks(options.mocks, _Vue)
+  addStubs(component, options.stubs, _Vue)
+
   if (
     (component.options && component.options.functional) ||
     component.functional
@@ -63,8 +57,6 @@ export default function createInstance (
     compileTemplate(component)
   }
 
-  addEventLogger(_Vue)
-
   // Replace globally registered components with components extended
   // from localVue. This makes sure the beforeMount mixins to add stubs
   // is applied to globally registered components.
@@ -78,77 +70,25 @@ export default function createInstance (
     }
   }
 
-  const stubComponents = createComponentStubs(
-    component.components,
-    // $FlowIgnore
-    options.stubs
+  extendExtendedComponents(
+    component,
+    _Vue,
+    options.logModifiedComponents,
+    instanceOptions.components
   )
-  if (options.stubs) {
-    instanceOptions.components = {
-      ...instanceOptions.components,
-      ...stubComponents
-    }
-  }
-  function addStubComponentsMixin () {
-    Object.assign(
-      this.$options.components,
-      stubComponents
-    )
-  }
-  _Vue.mixin({
-    beforeMount: addStubComponentsMixin,
-    // beforeCreate is for components created in node, which
-    // never mount
-    beforeCreate: addStubComponentsMixin
-  })
-  Object.keys(componentOptions.components || {}).forEach(c => {
-    if (
-      componentOptions.components[c].extendOptions &&
-      !instanceOptions.components[c]
-    ) {
-      if (options.logModifiedComponents) {
-        warn(
-          `an extended child component <${c}> has been modified ` +
-          `to ensure it has the correct instance properties. ` +
-          `This means it is not possible to find the component ` +
-          `with a component selector. To find the component, ` +
-          `you must stub it manually using the stubs mounting ` +
-          `option.`
-        )
-      }
-      instanceOptions.components[c] = _Vue.extend(
-        componentOptions.components[c]
-      )
-    }
-  })
 
   if (component.options) {
     component.options._base = _Vue
   }
 
-  function getExtendedComponent (component, instanceOptions) {
-    const extendedComponent = component.extend(instanceOptions)
-    // to keep the possible overridden prototype and _Vue mixins,
-    // we need change the proto chains manually
-    // @see https://github.com/vuejs/vue-test-utils/pull/856
-    // code below equals to
-    // `extendedComponent.prototype.__proto__.__proto__ = _Vue.prototype`
-    const extendedComponentProto =
-      Object.getPrototypeOf(extendedComponent.prototype)
-    Object.setPrototypeOf(extendedComponentProto, _Vue.prototype)
-
-    return extendedComponent
-  }
-
   // extend component from _Vue to add properties and mixins
-  const Constructor = typeof component === 'function'
-    ? getExtendedComponent(component, instanceOptions)
+  // extend does not work correctly for sub class components in Vue < 2.2
+  const Constructor = typeof component === 'function' && vueVersion < 2.3
+    ? component.extend(instanceOptions)
     : _Vue.extend(component).extend(instanceOptions)
 
-  Object.keys(instanceOptions.components || {}).forEach(key => {
-    Constructor.component(key, instanceOptions.components[key])
-    _Vue.component(key, instanceOptions.components[key])
-  })
+  // Keep reference to component mount was called with
+  Constructor._vueTestUtilsRoot = component
 
   if (options.slots) {
     compileTemplateForSlots(options.slots)

Diff for: packages/create-instance/extend-extended-components.js

@@ -0,0 +1,102 @@
+import { warn } from 'shared/util'
+
+function createdFrom (extendOptions, componentOptions) {
+  while (extendOptions) {
+    if (extendOptions === componentOptions) {
+      return true
+    }
+    if (extendOptions._vueTestUtilsRoot === componentOptions) {
+      return true
+    }
+    extendOptions = extendOptions.extendOptions
+  }
+}
+
+function resolveComponents (options = {}, components = {}) {
+  let extendOptions = options.extendOptions
+  while (extendOptions) {
+    resolveComponents(extendOptions, components)
+    extendOptions = extendOptions.extendOptions
+  }
+  let extendsFrom = options.extends
+  while (extendsFrom) {
+    resolveComponents(extendsFrom, components)
+    extendsFrom = extendsFrom.extends
+  }
+  Object.keys(options.components || {}).forEach((c) => {
+    components[c] = options.components[c]
+  })
+  return components
+}
+
+function shouldExtend (component) {
+  while (component) {
+    if (component.extendOptions) {
+      return true
+    }
+    component = component.extends
+  }
+}
+
+// Components created with Vue.extend are not created internally in Vue
+// by extending a localVue constructor. To make sure they inherit
+// properties add to a localVue constructor, we must create new components by
+// extending the original extended components from the localVue constructor.
+// We apply a global mixin that overwrites the components original
+// components with the extended components when they are created.
+export function extendExtendedComponents (
+  component,
+  _Vue,
+  logModifiedComponents,
+  excludedComponents = { },
+  stubAllComponents = false
+) {
+  const extendedComponents = Object.create(null)
+  const components = resolveComponents(component)
+
+  Object.keys(components).forEach(c => {
+    const comp = components[c]
+    const shouldExtendComponent =
+      (shouldExtend(comp) &&
+      !excludedComponents[c]) ||
+      stubAllComponents
+    if (shouldExtendComponent) {
+      if (logModifiedComponents) {
+        warn(
+          `The child component <${c}> has been modified to ensure ` +
+          `it is created with properties injected by Vue Test Utils. \n` +
+          `This is because the component was created with Vue.extend, ` +
+          `or uses the Vue Class Component decorator. \n` +
+          `Because the component has been modified, it is not possible ` +
+          `to find it with a component selector. To find the ` +
+          `component, you must stub it manually using the stubs mounting ` +
+          `option, or use a name or ref selector. \n` +
+          `You can hide this warning by setting the Vue Test Utils ` +
+          `config.logModifiedComponents option to false.`
+        )
+      }
+      extendedComponents[c] = _Vue.extend(comp)
+    }
+    // If a component has been replaced with an extended component
+    // all its child components must also be replaced.
+    extendExtendedComponents(
+      comp,
+      _Vue,
+      logModifiedComponents,
+      {},
+      shouldExtendComponent
+    )
+  })
+  if (extendedComponents) {
+    _Vue.mixin({
+      created () {
+        if (createdFrom(this.constructor, component)) {
+          Object.assign(
+            this.$options.components,
+            extendedComponents
+          )
+        }
+      }
+    })
+  }
+}

Diff for: packages/create-instance/extract-instance-options.js

@@ -10,13 +10,17 @@ const MOUNTING_OPTIONS = [
   'clone',
   'attrs',
   'listeners',
-  'propsData'
+  'propsData',
+  'logModifiedComponents',
+  'sync'
 ]
 
 export default function extractInstanceOptions (
   options: Object
 ): Object {
-  const instanceOptions = { ...options }
+  const instanceOptions = {
+    ...options
+  }
   MOUNTING_OPTIONS.forEach(mountingOption => {
     delete instanceOptions[mountingOption]
   })

Diff for: packages/shared/merge-options.js

@@ -1,18 +1,17 @@
 // @flow
+import { normalizeStubs } from './normalize'
 
 function getOption (option, config?: Object): any {
   if (option || (config && Object.keys(config).length > 0)) {
     if (option instanceof Function) {
       return option
-    } else if (Array.isArray(option)) {
-      return [...option, ...Object.keys(config || {})]
-    } else if (config instanceof Function) {
+    }
+    if (config instanceof Function) {
       throw new Error(`Config can't be a Function.`)
-    } else {
-      return {
-        ...config,
-        ...option
-      }
+    }
+    return {
+      ...config,
+      ...option
     }
   }
 }
@@ -25,7 +24,7 @@ export function mergeOptions (options: Options, config: Config): Options {
   return {
     ...options,
     logModifiedComponents: config.logModifiedComponents,
-    stubs: getOption(options.stubs, config.stubs),
+    stubs: getOption(normalizeStubs(options.stubs), config.stubs),
     mocks,
     methods,
     provide,

Diff for: packages/shared/normalize.js

@@ -0,0 +1,18 @@
+import { isPlainObject } from './validators'
+import { throwError } from './util'
+
+export function normalizeStubs (stubs = {}) {
+  if (isPlainObject(stubs)) {
+    return stubs
+  }
+  if (Array.isArray(stubs)) {
+    return stubs.reduce((acc, stub) => {
+      if (typeof stub !== 'string') {
+        throwError('each item in an options.stubs array must be a string')
+      }
+      acc[stub] = true
+      return acc
+    }, {})
+  }
+  throwError('options.stubs must be an object or an Array')
+}