RxJS v6 TimeoutError is missing name property

[felixfbecker]

RxJS version: 6.0.0

Code to reproduce:

export const browserExtensionInstalled = fromEvent(document, 'custom-event').pipe(
    mapTo(true),
    timeout(500),
    catchError(err => {
        if (err.name === 'TimeoutError') {
            return [false]
        }
        throw err
    }),
)

Expected behavior:

Should emit false after 500ms.

Actual behavior:

Throws an error Error: Timeout has occurred. (worked in RxJS 5)

Additional information:

This broke in commit 2f395da#diff-cd4b33df1ab129e23dc2bc5c12d8369b

UnsubscriptionError still has the name set, but TimeoutError doesn't, and it's not mentioned in the release notes, so I assume this is an unintentional bug (in any case it can be reintroduced in a semver-patch).

rxjs/src/internal/util/UnsubscriptionError.ts

Lines 5 to 13 in b948e65

	export class UnsubscriptionError extends Error {
	constructor(public errors: any[]) {
	super(errors ?
	`${errors.length} errors occurred during unsubscription:
	${errors.map((err, i) => `${i + 1}) ${err.toString()}`).join('\n ')}` : '');
	this.name = 'UnsubscriptionError';
	(Object as any).setPrototypeOf(this, UnsubscriptionError.prototype);
	}
	}

rxjs/src/internal/util/TimeoutError.ts

Lines 8 to 13 in b948e65

	export class TimeoutError extends Error {
	constructor() {
	super('Timeout has occurred');
	(Object as any).setPrototypeOf(this, TimeoutError.prototype);
	}

Why not use instanceof? instanceof breaks when multiple RxJS versions are in play, or even just the same version had to be installed multiple times because deduping wasn't possible. It asserts the implementation, err.name asserts an interface. All browser errors use it (e.g. AbortError).

[cartant]

This might be the first issue that'll effect a 6.0.1 release. I wonder if you get a prize? 🤔

[martinsik]

This seems to be fixed in #3656.