Prop with validator breaks prop types for component

[KaelWD]

Version

3.0.2

Reproduction link

https://codesandbox.io/s/blissful-darwin-mi9ul

Steps to reproduce

Try to access props.type

What is expected?

No error

What is actually happening?

Property 'type' does not exist on type 'Readonly<...

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Removing the validator or using as Prop<string> fixes the error, but it should be inferred without breaking the component.

[HcySunYang]

Use arrow function instead, or explicitly add an annotation to this: validator(this: void, val: string){ ... }

[KaelWD]

Ah yeah it's vuejs/vue#8679 again, thanks.

[JensDll]

I would like to add that this is a design limitation in TypeScript; see this issue microsoft/TypeScript#38845. And I believe that the example under Annotating Props in the docs will have this problem as well.

[yyx990803]

/cc @vuejs/docs

[LinusBorg]

Documentation as been amended with proper instructions, we can close this here.

[kuanyui]

Still encountered the same issue even if following doc... (vue 3.0.7, typescript 4.2.3)
#2738 (comment)