Version

3.0.4

Reproduction link

https://github.com/MarcRoemmelt/vue-lost-proptypes

Steps to reproduce

1. Clone project
2. Install dependencies
3. Check App.vue intellisense for props-typings in setup(props) or this.$props

What is expected?

Type inference for all props should work regardless of custom-validator

What is actually happening?

If a validator function is present in any prop, the type inference breaks. Interestingly, if the validator is an arrow-function it it works.

This is a known issue and is a limitation of TypeScript handling circular inference of ThisType (which is only present if using a non-arrow function).

There is currently no fix for this (will have to be upstream in TS) so using arrow function is the recommended workaround.

This issue still exists even if using an arrow function as the validator of a prop. (vue 3.0.7, typescript 4.2.3)

@kuanyui You will still need to type the validators parameter:

size: {
  type: String,
  default: 'md',
  validator: (x: string) => { ... }
}

@kuanyui You will still need to type the validators parameter:

size: {
  type: String,
  default: 'md',
  validator: (x: string) => { ... }
}

@JensDll Wow magic it works! So fantastic! Thanks!