Fetch types are incompatible with "lib/dom" definitions

[kettanaito]

Bug Description

The Request interface exposed by Undici does not satisfy the same type from the global type definitions (lib/dom), and also missing properties according to the Fetch API specification:

undici/types/fetch.d.ts

Line 138 in d8d9a96

export declare class Request implements BodyMixin {

Reproducible By

As an example, consider the following code:

import { Request } from 'undicit'

function transform(req: globalThis.Request) {}

transform(new Request('/hello'))
// ^^^ Property 'referrer' is missing in type 'import(".../node_modules/undici/types/fetch").Request' but required in type 'Request'.ts(2345)

The referrer property is not present in the Undici's Request type definition while it's both required in lib/dom definitions and the Fetch API specification.

readonly attribute [USVString](https://webidl.spec.whatwg.org/#idl-USVString) [referrer](https://fetch.spec.whatwg.org/#dom-request-referrer);

Expected Behavior

Fetch API primitives such as Request, Response and Headers, are compatible with the global

Logs & Screenshots

No applicable logs.

Environment

• Node: v16.16.0
• Undici: ^5.20.0
• TypeScript: ^4.9.4

Additional context

I understand that I'm setting lib/dom as the source of truth here but I expect that shouldn't matter since:

1. Both Undici and lib/node aim to implement the Fetch API specification.
2. Undici is objectively missing some properties in its type definitions defined in the spec, like referrer.

Also, for context, I'm spotting this while building Interceptors (mswjs/interceptors#340) where I try using Undici as a Fetch polyfill to guarantee fetch primitives can be created in Node versions prior to global fetch.

I'd like to open a pull request to ensure this compliance after discussing this with the maintainers of this lib.

[KhafraDev]

Would you like to send in a PR to add the missing propert(y/ies) to Request?

[kettanaito]

@KhafraDev, absolutely! Will open a pull request tomorrow, we can follow up there. Thanks for a quick response on this.

[kettanaito]

Hey, @KhafraDev. I've opened a draft to improve typings of Undici. Would appreciate an early review of this and any potential discussion. Thanks.

[sharifzadesina]

It is interesting that this bug is not yet fixed. Can we do any help?

[mcollina]

It is interesting that this bug is not yet fixed. Can we do any help?

PRs are welcome!

[NatoBoram]

PRs are welcome!

Isn't #1964 already open?

[mcollina]

Actually it's abandoned with failing tests. A fresh one would be better.