1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
|
=== tests/cases/compiler/mappedTypeUnionConstrainTupleTreatedAsArrayLike.ts ===
type HomomorphicMappedType<T> = { [P in keyof T]: T[P] extends string ? boolean : null }
>HomomorphicMappedType : HomomorphicMappedType<T>
function test1<T extends [number] | [string]>(args: T) {
>test1 : <T extends [number] | [string]>(args: T) => void
>args : T
const arr: any[] = [] as HomomorphicMappedType<T>
>arr : any[]
>[] as HomomorphicMappedType<T> : HomomorphicMappedType<T>
>[] : []
const arr2: readonly any[] = [] as HomomorphicMappedType<T>
>arr2 : readonly any[]
>[] as HomomorphicMappedType<T> : HomomorphicMappedType<T>
>[] : []
}
function test2<T extends [number] | readonly [string]>(args: T) {
>test2 : <T extends [number] | readonly [string]>(args: T) => void
>args : T
const arr: any[] = [] as HomomorphicMappedType<T> // error
>arr : any[]
>[] as HomomorphicMappedType<T> : HomomorphicMappedType<T>
>[] : []
const arr2: readonly any[] = [] as HomomorphicMappedType<T>
>arr2 : readonly any[]
>[] as HomomorphicMappedType<T> : HomomorphicMappedType<T>
>[] : []
}
|
