如何将正确的类型关联函数参数作为元组返回?我想要一个函数根据其参数的元组类型返回其值。
下面的例子是一个 get
函数,但我想让它使用 getAll
函数和参数作为元组。
type PathImpl<T, Key extends keyof T> =
Key extends string
? T[Key] extends Record<string, any>
? | `${Key}.${PathImpl<T[Key], Exclude<keyof T[Key], keyof any[]>> & string}`
| `${Key}.${Exclude<keyof T[Key], keyof any[]> & string}`
: never
: never;
type PathImpl2<T> = PathImpl<T, keyof T> | keyof T;
type Path<T> = PathImpl2<T> extends string | keyof T ? PathImpl2<T> : keyof T;
type PathValue<T, P extends Path<T>> =
P extends `${infer Key}.${infer Rest}`
? Key extends keyof T
? Rest extends Path<T[Key]>
? PathValue<T[Key], Rest>
: never
: never
: P extends keyof T
? T[P]
: never;
declare function get<T, P extends Path<T>>(obj: T, path: P): PathValue<T, P>;
const object = {
firstName: "test",
lastName: "test1"
} as const;
get(object, "firstName");
declare function getAll<T, P extends Path<T>>(obj: T, args: P[]): PathValue<T, P>;
const data = getAll(object, ['firstName', 'lastName'])
// how to produce the type: ['test', 'test1']
答案 0 :(得分:1)
您可以使用映射类型来映射传入的元组。您还必须更改类型参数以捕获元组类型。
type MapAllPaths<T, P extends Path<T>[]> = {} & {
[K in keyof P ]: PathValue<T, P[K] & Path<T>>
}
declare function getAll<T, P extends [Path<T>] | Path<T>[]>(obj: T, args: P): MapAllPaths<T, P>;