feat: add parentComponent option (#846)

Author: eddyerburgh

docs/api/options.md

@@ -11,6 +11,7 @@ Options for `mount` and `shallowMount`. The options object can contain both Vue
 - [`attachToDocument`](#attachtodocument)
 - [`attrs`](#attrs)
 - [`listeners`](#listeners)
+- [`parentComponent`](#parentComponent)
 - [`provide`](#provide)
 - [`sync`](#sync)
 
@@ -182,6 +183,23 @@ Set the component instance's `$attrs` object.
 
 Set the component instance's `$listeners` object.
 
+## parentComponent
+
+- type: `Object`
+
+Component to use as parent for mounted component.
+
+Example:
+
+```js
+import Foo from './Foo.vue'
+
+const wrapper = shallowMount(Component, {
+  parentComponent: Foo
+})
+expect(wrapper.vm.$parent.name).toBe('foo')
+```
+
 ## provide
 
 - type: `Object`

flow/options.flow.js

@@ -12,6 +12,7 @@ declare type Options = {
   context?: Object,
   attrs?: { [key: string]: string },
   listeners?: { [key: string]: Function | Array<Function> },
+  parentComponent?: Object,
   logModifiedComponents?: boolean,
   sync?: boolean
 };

packages/create-instance/create-instance.js

@@ -8,7 +8,7 @@ import { throwError, warn, vueVersion } from 'shared/util'
 import { compileTemplate } from 'shared/compile-template'
 import extractInstanceOptions from './extract-instance-options'
 import createFunctionalComponent from './create-functional-component'
-import { componentNeedsCompiling } from 'shared/validators'
+import { componentNeedsCompiling, isPlainObject } from 'shared/validators'
 import { validateSlots } from './validate-slots'
 import createScopedSlots from './create-scoped-slots'
 
@@ -138,25 +138,32 @@ export default function createInstance (
 
   const scopedSlots = createScopedSlots(options.scopedSlots)
 
-  const Parent = _Vue.extend({
-    provide: options.provide,
-    render (h) {
-      const slots = options.slots
-        ? createSlotVNodes(this, options.slots)
-        : undefined
-      return h(
-        Constructor,
-        {
-          ref: 'vm',
-          props: options.propsData,
-          on: options.listeners,
-          attrs: options.attrs,
-          scopedSlots
-        },
-        slots
-      )
-    }
-  })
+  if (options.parentComponent && !isPlainObject(options.parentComponent)) {
+    throwError(
+      `options.parentComponent should be a valid Vue component ` +
+      `options object`
+    )
+  }
+
+  const parentComponentOptions = options.parentComponent || {}
+  parentComponentOptions.provide = options.provide
+  parentComponentOptions.render = function (h) {
+    const slots = options.slots
+      ? createSlotVNodes(this, options.slots)
+      : undefined
+    return h(
+      Constructor,
+      {
+        ref: 'vm',
+        props: options.propsData,
+        on: options.listeners,
+        attrs: options.attrs,
+        scopedSlots
+      },
+      slots
+    )
+  }
+  const Parent = _Vue.extend(parentComponentOptions)
 
   return new Parent()
 }

packages/shared/util.js

@@ -34,7 +34,3 @@ export const hyphenate = (str: string): string =>
 export const vueVersion = Number(
   `${Vue.version.split('.')[0]}.${Vue.version.split('.')[1]}`
 )
-
-export function isPlainObject (obj: any): boolean {
-  return Object.prototype.toString.call(obj) === '[object Object]'
-}

packages/shared/validators.js

@@ -41,6 +41,10 @@ export function isVueComponent (component: any): boolean {
     return true
   }
 
+  if (typeof component.template === 'string') {
+    return true
+  }
+
   return typeof component.render === 'function'
 }
 
@@ -81,3 +85,7 @@ export function templateContainsComponent (
     return re.test(template)
   })
 }
+
+export function isPlainObject (obj: any): boolean {
+  return Object.prototype.toString.call(obj) === '[object Object]'
+}

packages/test-utils/src/recursively-set-data.js

@@ -1,4 +1,4 @@
-import { isPlainObject } from 'shared/util'
+import { isPlainObject } from 'shared/validators'
 
 export function recursivelySetData (vm, target, obj) {
   Object.keys(obj).forEach(key => {

packages/test-utils/types/index.d.ts

@@ -126,6 +126,7 @@ interface MountOptions<V extends Vue> extends ComponentOptions<V> {
   context?: VNodeData
   localVue?: typeof Vue
   mocks?: object
+  parentComponent?: Component
   slots?: Slots
   scopedSlots?: Record<string, string>
   stubs?: Stubs,

packages/test-utils/types/test/mount.ts

@@ -28,6 +28,7 @@ mount(ClassComponent, {
   mocks: {
     $store: store
   },
+  parentComponent: normalOptions,
   slots: {
     default: `<div>Foo</div>`,
     foo: [normalOptions, functionalOptions],

test/specs/mounting-options/parentComponent.spec.js

@@ -0,0 +1,35 @@
+import { describeWithMountingMethods } from '~resources/utils'
+
+describeWithMountingMethods('options.parentComponent', mountingMethod => {
+  it('mounts component with $parent set to options.parentComponent', () => {
+    const Parent = {
+      data: () => ({
+        customName: 'Parent Name'
+      })
+    }
+    const TestComponent = {
+      template: '<div>{{$parent.customName}}</div>'
+    }
+    const wrapper = mountingMethod(TestComponent, {
+      parentComponent: Parent
+    })
+    const HTML = mountingMethod.name === 'renderToString'
+      ? wrapper
+      : wrapper.html()
+    expect(HTML).to.contain('Parent Name')
+  })
+
+  it('validates parentComponent option', () => {
+    ;['str', 123, [], () => {}].forEach(invalidParent => {
+      const TestComponent = {
+        template: '<div>{{$parent.customName}}</div>'
+      }
+      const fn = () => mountingMethod(TestComponent, {
+        parentComponent: invalidParent
+      })
+      const message = '[vue-test-utils]: options.parentComponent should be a valid Vue component options object'
+      expect(fn).to.throw()
+        .with.property('message', message)
+    })
+  })
+})

test/specs/mounting-options/stubs.spec.js

@@ -37,8 +37,8 @@ describeWithMountingMethods('options.stub', mountingMethod => {
     const SubclassedComponent = Vue.extend({ template: '<div></div>' })
     mountingMethod(ComponentWithChild, {
       stubs: {
-        ChildComponent: ComponentAsAClass,
-        ChildComponent2: ComponentWithRender,
+        ChildComponent: ComponentWithRender,
+        ChildComponent2: ComponentAsAClass,
         ChildComponent3: ComponentWithoutRender,
         ChildComponent4: ExtendedComponent,
         ChildComponent5: SubclassedComponent