fix: keep the overrides prototype information of component (#856)

packages/create-instance/create-instance.js

@@ -126,7 +126,9 @@ export default function createInstance (
  component.options._base = _Vue
  }
 
- const Constructor = vueVersion < 2.3 && typeof component === 'function'
+ // when component constructed by Vue.extend,
+ // use its own extend method to keep component information
+ const Constructor = typeof component === 'function'
  ? component.extend(instanceOptions)
  : _Vue.extend(component).extend(instanceOptions)
 

test/specs/mount.spec.js

@@ -153,6 +153,28 @@ describeRunIf(process.env.TEST_ENV !== 'node', 'mount', () => {
  expect(stub).not.called
  })
 
+ it('overrides component prototype', () => {
+ const mountSpy = sinon.spy()
+ const destroySpy = sinon.spy()
+ const Component = Vue.extend({})
+ const { $mount: originalMount, $destroy: originalDestroy } = Component.prototype
+ Component.prototype.$mount = function (...args) {
+ mountSpy()
+ originalMount.apply(this, args)
+ return this
+ }
+ Component.prototype.$destroy = function () {
+ originalDestroy.apply(this)
+ destroySpy()
+ }
+
+ const wrapper = mount(Component)
+ expect(mountSpy).called
+ expect(destroySpy).not.called
+ wrapper.destroy()
+ expect(destroySpy).called
+ })
+
  // Problems accessing options of twice extended components in Vue < 2.3
  itDoNotRunIf(vueVersion < 2.3, 'compiles extended components', () => {
  const TestComponent = Vue.component('test-component', {