Change type of exported failure helpers from class to interface

[eltigerchino]

Through this I'm realizing just now that we're not returning "is this interface" but rather "is this class" from that. We should definitely change it for the new function to refer to the interface instead, not sure if it's seen as a breaking change to change it for the others, too

Originally posted by @dummdidumm in #12878 (comment)

kit/packages/kit/types/index.d.ts

Lines 1837 to 1851 in 598129a

	class HttpError_1 {
	constructor(status: number, body: {
	message: string;
	} extends App.Error ? (App.Error | string | undefined) : App.Error);
	status: number;
	body: App.Error;
	toString(): string;
	}
	class Redirect_1 {
	constructor(status: 300 | 301 | 302 | 303 | 304 | 305 | 306 | 307 | 308, location: string);
	status: 301 | 302 | 303 | 307 | 308 | 300 | 304 | 305 | 306;
	location: string;
	}

Proposed solution

Change the types to use the interface instead of the class.

/**
 * Checks whether this is an action failure thrown by {@link fail}.
 * @param {unknown} e The object to check.
- * @return {e is ActionFailure}
+ * @return {e is import('./public.js').ActionFailure}
 */
export function isActionFailure(e) {
	return e instanceof ActionFailure;
}

kit/packages/kit/src/exports/index.js

Lines 72 to 82 in 598129a

	/**
	* Checks whether this is an error thrown by {@link error}.
	* @template {number} T
	* @param {unknown} e
	* @param {T} [status] The status to filter for.
	* @return {e is (HttpError & { status: T extends undefined ? never : T })}
	*/
	export function isHttpError(e, status) {
	if (!(e instanceof HttpError)) return false;
	return !status || e.status === status;
	}

kit/packages/kit/src/exports/index.js

Lines 105 to 112 in 598129a

	/**
	* Checks whether this is a redirect thrown by {@link redirect}.
	* @param {unknown} e The object to check.
	* @return {e is Redirect}
	*/
	export function isRedirect(e) {
	return e instanceof Redirect;
	}