fix: revert automatic two way sync of v-model prop values

closes vuejs#440

src/emit.ts

@@ -64,16 +64,4 @@ export const recordEvent = (
 
   // Record the event message sent by the emit
   events[cid][event].push(args)
-
-  if (event.startsWith('update:')) {
-    if (args.length !== 1) {
-      throw new Error(
-        'Two-way bound properties have to emit a single value. ' +
-          args.length +
-          ' values given.'
-      )
-    }
-
-    vm.props[event.slice('update:'.length)] = args[0]
-  }
 }

tests/props.spec.ts

@@ -1,7 +1,7 @@
 import { mount } from '../src'
 import WithProps from './components/WithProps.vue'
 import Hello from './components/Hello.vue'
-import { defineComponent } from 'vue'
+import { defineComponent, h } from 'vue'
 
 describe('props', () => {
   it('returns a single prop applied to a component', () => {
@@ -103,7 +103,8 @@ describe('props', () => {
 
     const wrapper = mount(component, {
       props: {
-        modelValue: 1
+        modelValue: 1,
+        'onUpdate:modelValue': async (modelValue: number) => wrapper.setProps({ modelValue })
       }
     })
 
@@ -185,4 +186,33 @@ describe('props', () => {
       foo: 'new value'
     })
   })
+
+  it('https://github.com/vuejs/vue-test-utils-next/issues/440', async () => {
+    const Foo = defineComponent({
+      name: 'Foo',
+      props: {
+        foo: String,
+      },
+      emits: ['update:foo'],
+      setup (props, ctx) {
+        return () => h('div', {
+          onClick: () => {
+            ctx.emit('update:foo', 'world')
+          },
+        }, props.foo)
+      }
+    })
+
+    const wrapper = mount(Foo, {
+      props: {
+        foo: 'hello'
+      }
+    })
+
+    expect(wrapper.text()).toEqual('hello')
+
+    await wrapper.trigger('click')
+
+    expect(wrapper.text()).toEqual('hello')
+  })
 })