packages/kit/src/runtime/control.js

export class HttpError {
	/**
	 * @param {number} status
	 * @param {{message: string} extends App.Error ? (App.Error | string | undefined) : App.Error} body
	 */
	constructor(status, body) {
		this.status = status;
		if (typeof body === 'string') {
			this.body = { message: body };
		} else if (body) {
			this.body = body;
		} else {
			this.body = { message: `Error: ${status}` };
		}
	}

	toString() {
		return JSON.stringify(this.body);
	}
}

export class Redirect {
	/**
	 * @param {300 | 301 | 302 | 303 | 304 | 305 | 306 | 307 | 308} status
	 * @param {string} location
	 */
	constructor(status, location) {
		this.status = status;
		this.location = location;
	}
}

/**
 * An error that was thrown from within the SvelteKit runtime that is not fatal and doesn't result in a 500, such as a 404.
 * `SvelteKitError` goes through `handleError`.
 * @extends Error
 */
export class SvelteKitError extends Error {
	/**
	 * @param {number} status
	 * @param {string} text
	 * @param {string} message
	 */
	constructor(status, text, message) {
		super(message);
		this.status = status;
		this.text = text;
	}
}

/**
 * @template {Record<string, unknown> | undefined} [T=undefined]
 */
export class ActionFailure {
	/**
	 * @param {number} status
	 * @param {T} data
	 */
	constructor(status, data) {
		this.status = status;
		this.data = data;
	}
}