webpack/lib/errors/TopLevelThisWarning.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 Alexander Akait @alexander-akait
*/

"use strict";

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

/**
 * @typedef {object} TopLevelThisDetails
 * @property {string} name the module, by request
 * @property {number} count how many times it reads `this` at the top level
 */

class TopLevelThisWarning extends WebpackError {
	/**
	 * Creates an instance of TopLevelThisWarning.
	 * @param {TopLevelThisDetails[]} modules the modules that do it
	 * @param {number} total how many such reads there are in all
	 */
	constructor(modules, total) {
		const list = modules.map((it) => `\n  ${it.name} (${it.count})`).join("");

		super(
			`top-level this: ${total} ${total === 1 ? "read" : "reads"} of 'this' at the top level of an ES module:${list}\nwebpack is treating these as ES modules, where 'this' is 'undefined' at the top level rather than 'module.exports' — so a file that worked as CommonJS reads nothing once it is bundled this way. A single 'import' or 'export' is enough to make 'javascript/auto' decide a file is an ES module. Use 'globalThis' where the global object was meant, 'import.meta' for anything about the module, or give the file a '.cjs' extension to keep it CommonJS.\nFor more info visit https://webpack.js.org/api/module-variables/#importmeta`
		);

		/** @type {string} */
		this.name = "TopLevelThisWarning";
	}
}

module.exports = TopLevelThisWarning;