Description
Vue version
3.2.36
Link to minimal reproduction
https://stackblitz.com/edit/vitejs-vite-hguguz?file=tsconfig.json,src%2FApp.vue&terminal=dev
Steps to reproduce
- Open a terminal
- Run
vue-tsc --noEmit
What is expected?
The command vue-tsc --noEmit runs without errors.
What is actually happening?
The command vue-tsc --noEmit gives type errors (output below was copied from StackBlitz reproduction):
src/App.vue:8:4 - error TS2375: Type '{ alt: undefined; }' is not assignable to type 'ElementAttrs<ImgHTMLAttributes>' with 'exactOptionalPropertyTypes: true'. Consider adding 'undefined' to the types of the target's properties.
Type '{ alt: undefined; }' is not assignable to type 'ImgHTMLAttributes' with 'exactOptionalPropertyTypes: true'. Consider adding 'undefined' to the types of the target's properties.
Types of property 'alt' are incompatible.
Type 'undefined' is not assignable to type 'string'.
8 <img :alt="msg" />
~~~
Found 1 error in src/App.vue:8
System Info
No response
Any additional comments?
TypeScript 4.4 introduced a new option --exactOptionalPropertyTypes which specifies that optional property types should be interpreted exactly as written, meaning that | undefined is not added to the type.
The *HTMLAttributes interfaces in @vue/runtime-dom are lacking the | undefined type, meaning that vue-tsc with enabled --exactOptionalPropertyTypesflag will fail.
Regarding the StackBlitz reproduction, the ImgHTMLAttributes interface should be defined at least as
export interface ImgHTMLAttributes extends HTMLAttributes {
alt?: undefined | string
crossorigin?: 'anonymous' | 'use-credentials' | ''
decoding?: 'async' | 'auto' | 'sync'
height?: Numberish
sizes?: string
src?: string
srcset?: string
usemap?: string
width?: Numberish
}
instead of
export interface ImgHTMLAttributes extends HTMLAttributes {
alt?: string
crossorigin?: 'anonymous' | 'use-credentials' | ''
decoding?: 'async' | 'auto' | 'sync'
height?: Numberish
sizes?: string
src?: string
srcset?: string
usemap?: string
width?: Numberish
}
However, for sake of completion the | undefined type needs to be added to all optional properties, not only the alt? one.