webpack/lib/AbstractMethodError.js

Packs ECMAScript/CommonJs/AMD modules for the browser. Allows you to split your codebase into multiple bundles, which can be loaded on demand. Supports loaders to preprocess files, i.e. json, jsx, es7, css, less, ... and your custom stuff.

/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Ivan Kopeykin @vankop
*/

"use strict";

const WebpackError = require("./WebpackError");

const CURRENT_METHOD_REGEXP = /at ([a-zA-Z0-9_.]*)/;

/**
 * Creates the error message shown when an abstract API is called without
 * being implemented by a subclass.
 * @param {string=} method method name
 * @returns {string} message
 */
function createMessage(method) {
	return `Abstract method${method ? ` ${method}` : ""}. Must be overridden.`;
}

/**
 * Captures a stack trace so the calling method name can be folded into the
 * final abstract-method error message.
 * @constructor
 */
function Message() {
	/** @type {string | undefined} */
	this.stack = undefined;
	Error.captureStackTrace(this);
	/** @type {RegExpMatchArray | null} */
	const match =
		/** @type {string} */
		(/** @type {unknown} */ (this.stack))
			.split("\n")[3]
			.match(CURRENT_METHOD_REGEXP);

	this.message = match && match[1] ? createMessage(match[1]) : createMessage();
}

/**
 * Error thrown when code reaches a method that is intended to be overridden by
 * a subclass.
 * @example
 * ```js
 * class FooClass {
 *     abstractMethod() {
 *         throw new AbstractMethodError(); // error message: Abstract method FooClass.abstractMethod. Must be overridden.
 *     }
 * }
 * ```
 */
class AbstractMethodError extends WebpackError {
	/**
	 * Creates an error whose message points at the abstract method that was
	 * invoked.
	 */
	constructor() {
		super(new Message().message);
		/** @type {string} */
		this.name = "AbstractMethodError";
	}
}

module.exports = AbstractMethodError;