Abnormal result when register onCleanup conditionally

[smoonsf]

Vue version

3.2.47

Link to minimal reproduction

https://sfc.vuejs.org/#__DEV__eNp9UVtqwzAQvMpWP3HAtugDCqkTUgo9haA49tpxoxeSnHwY372SnHdL/ePdnZ0ZdjSQd63zfY9kQQpbmU47sOh6vWKyE1oZBwMYbFI4lK7awgiNUQJmnjFjkslKSeug4WULy7CXNCW3OH8LWGQkAUshkXj4jNVXCkp+cCxlr+ewXMHAJAClEKQUx5yrNplFLtYPsxSOzKAJ0DVnqfnEhItcklwEw3ejWIWdPxQBxqkYmYxVQaccfAK+cSg0Lx36DqDYPq6GYTp3HAvq2zje9M4pCeuKd9Vuycgxj4fwZyTuADjVthzjPp0IHijo2YCkZEo8E6XOv62S/k3iLewIWEYWp+sY8U8Qeka2zmm7oLSXetfmlRJ07TFqeuk6gVmtxPo5f8pfXmndWXc9z9GKbGPUwaLxjoykV+LUD/doMoOyRoPmX7O73RvDO+yX6Sl8Mv4ABlLaxw==

Steps to reproduce

1. repeat clicking toggle.
2. see console log.

What is expected?

cleanup function should not be called in not registering onCleanup condition.

What is actually happening?

cleanup function called in not registering onCleanup condition.

System Info

No response

Any additional comments?

No response

[AlexVagrant]

Your if condition controls when registers onCleanup function. it does not control when vue call onCleanup function.

If you register an onCleanup function it would always exist. so you will see the watch method is triggered, and the onCleanup method is also triggered

[smoonsf]

I see. But there is no way to unregister onCleanup right? Then condition should be inside cleanup function.

I think official guide about onCleanup is unclear for understanding its logic. 😢

[cyrilluce]

Same issue as #5151