How to correctly type an instance returned by got.extend

[jogold]

What would you like to discuss?

Given the following client:

const jsonClient = got.extend({
  responseType: 'json',
  resolveBodyOnly: true
});

Doing:

const response = await jsonClient('https://httpbin.org/json');

hints TypeScript to believe that response is of type Response<string> while it should be unknown.

How can I correctly type jsonClient to take into account my options?

Checklist

• I have read the documentation.

[szmarczak]

For now you need to cast it manually.

[chinesedfan]

In theory, it can be achieved by conditional types. See examples like sindresorhus/pify#76.

@szmarczak If you agree with this kind of mechanism, I can send a PR to handle options.resolveBodyOnly. But types related codes will require lots of refactors and become a little complex.

[maxpain]

Any news about this?

[ejmartin504]

I agree that the typing should be correct here, likely by using conditional types as @chinesedfan mentioned. I'd like to point out one workaround for this specific instance of got.extend, which my team used quite effectively in our project to get better typing: use .json

From the docs:

// This
const body = await got(url).json();

// is semantically the same as this
const body = await got(url, {responseType: 'json', resolveBodyOnly: true}); 

[TkaczykAdam]

I am a newbie in the TS world, I didn't want to type it as any. For a quick workaround, I just add the redundant .json()
@szmarczak please let us know when it will be fixed or provide an example of how to do it correctly 😃

[metelliandrea]

As workaround I put my response in a const and cast it to any (I guess a custom interface works too), in you case:

const jsonClient = got.extend({
  responseType: 'json',
  resolveBodyOnly: true
});

const response = await jsonClient('https://httpbin.org/json');
const data = response as any;

// other stuffs with data

Hope it help! 😃