Union types are not unwrapped properly

[jods4]

Vue version

3.313

Link to minimal reproduction

https://play.vuejs.org/#eNp9UctOwzAQ/JWVL7RSSUEVl5CmgqoHkFpQgZsvUbp5FMe27E0fivLv2KkaioR6seyd2fHMbsOetA52NbKQRTY1pSawSLUGkch8yhlZzmIuy0orQ9DAl9ybRK8xG4Hxh7tBC5lRFdw4mRsuuUyVtASVzWEKy4SKwCRyo6rBEGK4u32AmW8dNCCTCkPg7Kg4g3YIIchaiEcvQUeNsOwU+h8jX1SZF44dKRqf/Dp37kFYaZEQuhdAVNzHTeOJs8B/EgiUORXQttHYQb73gs9GLqXznJV5sLVKulE0XoWzVFW6FGjeNJUuE2chdIjHEiHU/rWrkalxdK6nBabf/9S39uBrnL0btGh2yFmPUWJypBO8+Fjhwd17sFKbWjj2FXCNVonaezzRnmu5cbYveJ3bl26Jpcw/7eJAKO051B+jlkyZ0sptYu6j9ASPtx2LM7fp+ZXZ/OaZBJOuj8uWtT+kU81Z

Steps to reproduce

Create a type that is the union of a Ref of a non-primitive type and null, e.g. type X = Ref<{ name: string }> | null.

What is expected?

UnwrapRef<X> should be { name: string } | null.

What is actually happening?

Well... in TS script block it looks like UnwrapRef<X> is right, but when looked at inside the template block, it's still Ref<{ name: string }> | null. (see repro link)

As a consequence, using x in template (where refs are unwrapped automatically) fails type-checking as TS doesn't see the right type.

System Info

See repro in Vue SFC Playground.

Any additional comments?

This is the same issue as #3990 which was fixed. Maybe it regressed in a later release?

[LinusBorg]

Since it works fine in the script block and only fails in the template, this doesn't seem to be a regression of #3990, I'd rather think this is a bug in vue-language-tools

[jods4]

@johnsoncodehk do you think the bug is specifically in vue-language-tools?
I can re-create the issue there but there was a bit of back-and-forth at #3990 time so I'd like to be sure.

[johnsoncodehk]

The problem seems to be the inconsistency between the unref behavior of defineComponent setup return and UnwrapRef.

https://play.vuejs.org/#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