fix: no unnecessary extend

packages/create-instance/create-instance.js

@@ -90,8 +90,8 @@ export default function createInstance (
   // extend component from _Vue to add properties and mixins
   // extend does not work correctly for sub class components in Vue < 2.2
   const Constructor = typeof component === 'function'
-    ? _Vue.extend(component.options).extend(instanceOptions)
-    : _Vue.extend(component).extend(instanceOptions)
+    ? _Vue.extend(component.options)
+    : _Vue.extend(component)
 
   // used to identify extended component using constructor
   Constructor.options.$_vueTestUtils_original = component
@@ -151,5 +151,5 @@ export default function createInstance (
   }
   const Parent = _Vue.extend(parentComponentOptions)
 
-  return new Parent()
+  return new Parent(instanceOptions)
 }

packages/test-utils/src/wrapper.js

@@ -675,11 +675,13 @@ export default class Wrapper implements BaseWrapper {
    */
   setMethods (methods: Object): void {
     if (!this.isVueInstance()) {
-      throwError(
-        `wrapper.setMethods() can only be called on a Vue ` +
-        `instance`
-      )
+      throwError(`wrapper.setMethods() can only be called on a Vue instance`)
     }
+    // the methods object is a reference to the original component methods
+    // object. So before making any changes we need to replace vm.methods with
+    // an object that we can change safely.
+    this.vm.$options.methods = Object.create(this.vm.$options.methods)
+
     Object.keys(methods).forEach(key => {
       // $FlowIgnore : Problem with possibly null this.vm
       this.vm[key] = methods[key]

test/specs/config.spec.js

@@ -68,21 +68,6 @@ describeWithShallowAndMount('config', mountingMethod => {
     localVue.prototype.$t = undefined
   })
 
-  it('overrides a method', () => {
-    const testComponent = {
-      template: `
-        <div>{{ val() }}</div>
-      `
-    }
-
-    config.methods['val'] = () => 'method'
-
-    const wrapper = mountingMethod(testComponent)
-
-    expect(wrapper.vm.val()).to.equal('method')
-    expect(wrapper.text()).to.equal('method')
-  })
-
   it("doesn't stub transition when config.stubs.transition is set to false", () => {
     const testComponent = {
       template: `

test/specs/mount.spec.js

@@ -5,7 +5,7 @@ import Component from '~resources/components/component.vue'
 import ComponentWithProps from '~resources/components/component-with-props.vue'
 import ComponentWithMixin from '~resources/components/component-with-mixin.vue'
 import ComponentAsAClass from '~resources/components/component-as-a-class.vue'
-import { injectSupported, vueVersion } from '~resources/utils'
+import { vueVersion } from '~resources/utils'
 import { describeRunIf, itDoNotRunIf, itSkipIf } from 'conditional-specs'
 import Vuex from 'vuex'
 
@@ -161,27 +161,6 @@ describeRunIf(process.env.TEST_ENV !== 'node', 'mount', () => {
     expect(wrapper.html()).to.equal(`<div>foo</div>`)
   })
 
-  itDoNotRunIf(
-    vueVersion < 2.3,
-    'overrides methods', () => {
-      const stub = sinon.stub()
-      const TestComponent = Vue.extend({
-        template: '<div />',
-        methods: {
-          callStub () {
-            stub()
-          }
-        }
-      })
-      mount(TestComponent, {
-        methods: {
-          callStub () {}
-        }
-      }).vm.callStub()
-
-      expect(stub).not.called
-    })
-
   it.skip('overrides component prototype', () => {
     const mountSpy = sinon.spy()
     const destroySpy = sinon.spy()
@@ -235,9 +214,6 @@ describeRunIf(process.env.TEST_ENV !== 'node', 'mount', () => {
         render: h => h('div')
       },
       {
-        provide: {
-          prop: 'val'
-        },
         attachToDocument: 'attachToDocument',
         mocks: {
           prop: 'val'
@@ -257,9 +233,6 @@ describeRunIf(process.env.TEST_ENV !== 'node', 'mount', () => {
         }
       }
     )
-    if (injectSupported) {
-      expect(typeof wrapper.vm.$options.provide).to.equal('object')
-    }
 
     expect(wrapper.vm.$options.attachToDocument).to.equal(undefined)
     expect(wrapper.vm.$options.mocks).to.equal(undefined)
@@ -373,32 +346,6 @@ describeRunIf(process.env.TEST_ENV !== 'node', 'mount', () => {
     expect(wrapper.html()).to.equal(`<div height="50px" extra="attr"><p class="prop-1">prop1</p> <p class="prop-2"></p></div>`)
   })
 
-  it('overwrites the component options with the instance options', () => {
-    const Component = {
-      template: '<div>{{ foo() }}{{ bar() }}{{ baz() }}</div>',
-      methods: {
-        foo () {
-          return 'a'
-        },
-        bar () {
-          return 'b'
-        }
-      }
-    }
-    const options = {
-      methods: {
-        bar () {
-          return 'B'
-        },
-        baz () {
-          return 'C'
-        }
-      }
-    }
-    const wrapper = mount(Component, options)
-    expect(wrapper.text()).to.equal('aBC')
-  })
-
   it('handles inline components', () => {
     const ChildComponent = {
       render (h) {
@@ -415,4 +362,18 @@ describeRunIf(process.env.TEST_ENV !== 'node', 'mount', () => {
     })
     expect(wrapper.findAll(ChildComponent).length).to.equal(1)
   })
+
+  it('has correct own properties in options.components', () => {
+    const ChildComponent = {
+      template: '<div />'
+    }
+    const TestComponent = {
+      template: '<div />',
+      components: {
+        ChildComponent
+      }
+    }
+    const { vm } = mount(TestComponent)
+    expect(Object.keys(vm.$options.components)).to.contain('ChildComponent')
+  })
 })