Extend/typing regression in v11

[pasieronen]

Describe the bug

• Node.js version: 12.16.2
• OS & version: MacOS 10.15.4
• Typescript version: 3.8.3

Actual behavior

With got 11.0.2, this file results in TypeScript compiler error:

import got from 'got'

interface ServerResponse { foo: number }

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

jsonClient.post<ServerResponse>('http://localhost:3030/', { json: { bar: 1 } }).then(r => console.log(r.body.foo))

The error is:

test.ts:7:59 - error TS2769: No overload matches this call.
  Overload 1 of 16, '(url: string | URL, options?: Merge<Options, { isStream?: false; resolveBodyOnly?: false; responseType: "json"; }>): CancelableRequest<Response<ServerResponse>>', gave the following error.
    Argument of type '{ json: { bar: number; }; }' is not assignable to parameter of type 'Merge<Options, { isStream?: false; resolveBodyOnly?: false; responseType: "json"; }>'.
      Property 'responseType' is missing in type '{ json: { bar: number; }; }' but required in type '{ isStream?: false; resolveBodyOnly?: false; responseType: "json"; }'.
  Overload 2 of 16, '(url: string | URL, options?: Merge<Merge<Options, { isStream?: false; resolveBodyOnly?: false; responseType: "json"; }>, ResponseBodyOnly>): CancelableRequest<...>', gave the following error.
    Argument of type '{ json: { bar: number; }; }' is not assignable to parameter of type 'Merge<Merge<Options, { isStream?: false; resolveBodyOnly?: false; responseType: "json"; }>, ResponseBodyOnly>'.
      Property 'responseType' is missing in type '{ json: { bar: number; }; }' but required in type 'Pick<Merge<Options, { isStream?: false; resolveBodyOnly?: false; responseType: "json"; }>, "search" | "host" | "password" | "body" | "form" | "path" | "json" | "timeout" | ... 54 more ... | "sessionIdContext">'.

7 jsonClient.post<ServerResponse>('http://localhost:3030/', { json: { bar: 1 } }).then(r => console.log(r.body.foo))
                                                            ~~~~~~~~~~~~~~~~~~~~

  node_modules/got/dist/source/types.d.ts:28:5
    28     responseType: 'json';
           ~~~~~~~~~~~~
    'responseType' is declared here.
  node_modules/got/dist/source/types.d.ts:28:5
    28     responseType: 'json';
           ~~~~~~~~~~~~
    'responseType' is declared here.


Found 1 error.

Expected behavior

With got 10.7.0, the code compiles fine.

Code to reproduce

See above.

Checklist

• I have read the documentation.
• I have tried my code with the latest version of Node.js and Got.

[dscalzi]

Can confirm issue persists on v11.1.0.

[szmarczak]

I think this d3b972e may be the culprit, but haven't tried your example yet.

[dscalzi]

Here's a sample test that should work, yet fails with this regression (and should be added to the test suite).

test('sends plain objects as JSON using extended client', withServer, async (t, server, got) => {
	server.post('/', defaultEndpoint);

	const extendedClient = got.extend({ responseType: 'json' })

	const {body} = await extendedClient.post<{such: 'wow'}>({
		json: {such: 'wow'}
	});
	t.deepEqual(body, {such: 'wow'});
});

I don't think the <{such: 'wow'}> would be needed when this is fixed.

[dscalzi]

Just checked back to v10.7.0, this wasnt necessarily working as intended their either. It was using the responseType?: 'default' signature (defined here https://github.com/sindresorhus/got/blob/v10.7.0/source/create.ts#L49, removed in v11). In order for this to be properly implemented, there would have to be some kind of relationship between the InstanceDefaults and the options parameter of the GotRequestFunction.

[szmarczak]

This is actually a duplicate of #1117, closing.

[szmarczak]

Actually this shouldn't error, sorry.