求star

Challenge#

If we have a type which is wrapped type like Promise. How we can get a type which is inside the wrapped type?

For example: if we have Promise<ExampleType> how to get ExampleType?

type ExampleType = Promise<string[]>;

type Result = MyAwaited<ExampleType>; // string[]

Answer#

type MyAwaited<T extends Promise<unknown>> = T extends Promise<infer U>
  ? U extends Promise<unknown>
    ? MyAwaited<U>
    : U
  : never;