new URL() does not take URL object as base parameter

[felixfbecker]

TypeScript Version: 2.3.0

Code

// A *self-contained* demonstration of the problem follows...
const base = new URL('http://foo.com')
new URL('bar.html', base) 

Expected behavior:
Should compile

Actual behavior:

[ts]
Argument of type 'URL' is not assignable to parameter of type 'string | undefined'.
  Type 'URL' is not assignable to type 'string'.

Reference: https://developer.mozilla.org/en-US/docs/Web/API/URL/URL

[RyanCavanaugh]

The WG definition clearly defines this as a string https://url.spec.whatwg.org/#constructors , so the ability to pass a URL is just an implicit string conversion. Not sure why MDN documents this as if it's a different constructor.

[RyanCavanaugh]

... but the spec also shows an implicit string conversion as an example usage, so we should play along

[felixfbecker]

Yeah, you are right. It seems to accept URL objects for both input and base.

[mhegazy]

PRs welcomed. You can find more information about contributing lib.d.ts fixes at https://github.com/Microsoft/TypeScript/blob/master/CONTRIBUTING.md#contributing-libdts-fixes.

[TimvdLippe]

microsoft/TypeScript-DOM-lib-generator#332 has been merged and the update has been incorporated in this repository per https://github.com/Microsoft/TypeScript/blob/f2a1a428ea99ace495a8ca769b0a7c857ea6486a/lib/lib.dom.d.ts#L14860

[BarryThePenguin]

I think this can be closed now? It looks like the latest lib.dom.d.ts supports this

TypeScript/lib/lib.dom.d.ts

Line 16070 in a03227d

new(url: string, base?: string | URL): URL;