v3.0.0 `await res.json()` is `unknown`

this is unusable in typescript. v3.0.0 types the return value of await res.json() as unknown which means “this is dangerous info, you have no idea what it is. don’t touch it to avoid runtime errors.” but the point of a fetch request is to get the information back. you have to touch it. the type should stay any.

Reproduction

Steps to reproduce the behavior:

1. use node-fetch in a typescript project
2. try to build
3. see error

Expected behavior

for the build to succeed

[martijndeh]

I don’t mind defaulting to unknown instead of any, but can we have something like this json<T = unknown>(): Promise<T>; instead?

[martijndeh]

Aha, I see. Up to you of course. In my opinion it’s a bit more ergonomic to provide a type argument in the cases where you opt out of any runtime checks anyway — even if DefinitelyTyped thinks this is a common mistake. 😉

// Explicit type cast
const json1 = (await response.json()) as MyJson;
// Alternative type cast, not much better
const json2 = await (response.json() as Promise<MyJson>);
// Doesn't work anymore, 'unknown' is not assignable to type 'MyJson'
const json3: MyJson = await response.json();
// So pretty ;-)
const json4 = await response.json<MyJson>();