Typescript props type inference is incorrect

[wcldyx]

The type of msg should be string, but is inferred to be of type StringConstructor

import { createComponent } from 'vue-function-api'

    const MyComponent = createComponent({
        props: {
            msg: String
        },
        setup(props) {
            console.log(props.msg == '1'); // string | undefined
           // Error:(13, 25) TS2367: This condition will always return 'false' since the types 'StringConstructor' and '"1"' have no overlap.
        }
    })

[jsmith]

The PR from @ChuChencheng works great!

There are still issues with the required option. Here is an example from the RFC:

import { createComponent } from 'vue'

createComponent({
  props: {
    foo: {
      type: String,
      required: true,
    },
    bar: {
      type: String,
    },
  } as const,
  setup(props) {
    props.foo // "string" as expected
    props.bar // should be -> "string | undefined" but it actually "string"
  }
})

[beeplin]

@liximomo Do we have any plan to merge #16 and fix the required issue mentioned above by @jsmith ?

[IlCallo]

Trying it out as well, found some problems with props inference too.

props: {
    // complexObject: {
    //   type: (Object as unknown) as PropType<ComplexObject>,
    //   required: true,
    // }, <= inferred as  {type: ComplexObject, required true}, should be inferred as ComplexObject
    complexObject: (Object as unknown) as PropType<ComplexObject>, // <= inferred as ComplexObject, but there is no required, should be inferred as optional
  } as const,

In general, this section doesn't seem to be enforced in the actual implementation.

PS: remember to import PropType from vue-function-api, it has a different signature from the one into vue

PS2:

In 3.0, the props declaration is optional. If you don't want runtime props validation, you can omit props declaration and declare your expected prop types directly in TypeScript

If anyone is wondering, this isn't already working (as expected I guess)

[pauloevpr]

I have the same issue. Type inference does not work properly for props:

My workaround to avoid Typescript compilation issues is to use setup(props: any) {} to skip inference.