fix(defineModel): correct update with multiple changes in same tick

packages/runtime-core/__tests__/helpers/useModel.spec.ts

@@ -614,32 +614,31 @@ describe('useModel', () => {
  })
 
  test('set no change value', async () => {
- let changeChildMsg: (() => void) | null = null
+ let changeChildMsg!: (val: string) => void
 
- const compRender = vi.fn()
+ const setValue = vi.fn()
  const Comp = defineComponent({
  props: ['msg'],
  emits: ['update:msg'],
  setup(props) {
  const childMsg = useModel(props, 'msg')
- changeChildMsg = () => {
- childMsg.value = childMsg.value
- }
+ changeChildMsg = (val: string) => (childMsg.value = val)
  return () => {
  return childMsg.value
  }
  },
  })
 
- const msg = ref('HI')
+ const defaultVal = 'defaultVal'
+ const msg = ref(defaultVal)
  const Parent = defineComponent({
  setup() {
  return () =>
  h(Comp, {
  msg: msg.value,
  'onUpdate:msg': val => {
  msg.value = val
- compRender()
+ setValue()
  },
  })
  },
@@ -648,8 +647,14 @@ describe('useModel', () => {
  const root = nodeOps.createElement('div')
  render(h(Parent), root)
 
- expect(compRender).toBeCalledTimes(0)
- changeChildMsg!()
- expect(compRender).toBeCalledTimes(0)
+ expect(setValue).toBeCalledTimes(0)
+
+ changeChildMsg(defaultVal)
+ expect(setValue).toBeCalledTimes(0)
+
+ changeChildMsg('changed')
+ changeChildMsg(defaultVal)
+ expect(setValue).toBeCalledTimes(2)
+ expect(msg.value).toBe(defaultVal)
  })
 })

packages/runtime-core/src/helpers/useModel.ts

@@ -33,7 +33,7 @@ export function useModel(
 
  const res = customRef((track, trigger) => {
  let localValue: any
- let prevSetValue: any
+ let prevSetValue: any = EMPTY_OBJ
  let prevEmittedValue: any
 
  watchSyncEffect(() => {
@@ -51,7 +51,10 @@ export function useModel(
  },
 
  set(value) {
- if (!hasChanged(value, localValue)) {
+ if (
+ !hasChanged(value, localValue) &&
+ !(prevSetValue !== EMPTY_OBJ && hasChanged(value, prevSetValue))
+ ) {
  return
  }
  const rawProps = i.vnode!.props