Vue version

3.5.13

Link to minimal reproduction

https://play.vuejs.org/#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

Steps to reproduce

1. Fill the child component's input form with any sentences, it will edit the parent as well

What is expected?

The parent component value should not be edited because there is no emit or anything else that can update parent object value. This violence One Way Dataflow - child able to edit parent only from a Props

What is actually happening?

When the parent pass object to props then the child component receive and connect it to a variable using onMounted method, this make the parent also edited when child did.

const props = defineProps(
  {
    parentMsg: Object
  }
)

const childObj = ref({
  msg: ""
})

onMounted(() => {
  // parent will be editted as well even there is no emit
  childObj.value = props.parentMsg
})

System Info

Any additional comments?

for now, to avoid this issue. I connect the variable with object spread operator

onMounted(() => {
    childObj.value = {...props.parentObj};
});

No response