TypeScript 错误 - 预期为 1-2 arguments，但得到 0 或更多。 TS2556

Question

I was using this statement in JavaScript but when I try to use it in a TypeScript Project I get an error. It's complaining about the fetch(...args)

const fetcher = (...args) => fetch(...args).then(response => response.json());

Expected 1-2 arguments, but got 0 or more.  TS2556

Answer 1

This should help you:

const fetcher = (...args: [input: RequestInfo, init?: RequestInit | undefined]) => fetch(...args).then(response => response.json());

You should explicitly type arguments for fetch . It expects 1-2 arguments.

If you want to use rest operator, you should tell TS, that you also expect two arguments in your higher order function

Answer 2

Taking this answer from comment by @Keith which was the only thing that worked for me:

const fetcher = (...args: Parameters<typeof fetch>) => {
  fetch(...args).then(response => response.json());
}

Specifically adding this Parameters<typeof fetch> as the type of ...args