webpack/lib/WarnCaseSensitiveModulesPlugin.js

Packs CommonJs/AMD modules for the browser. Allows to split your codebase into multiple bundles, which can be loaded on demand. Support 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 Tobias Koppers @sokra
*/

"use strict";

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

/** @typedef {import("./Compiler")} Compiler */
/** @typedef {import("./Module")} Module */

class WarnCaseSensitiveModulesPlugin {
	/**
	 * Apply the plugin
	 * @param {Compiler} compiler the compiler instance
	 * @returns {void}
	 */
	apply(compiler) {
		compiler.hooks.compilation.tap(
			"WarnCaseSensitiveModulesPlugin",
			compilation => {
				compilation.hooks.seal.tap("WarnCaseSensitiveModulesPlugin", () => {
					/** @type {Map<string, Map<string, Module>>} */
					const moduleWithoutCase = new Map();
					for (const module of compilation.modules) {
						const identifier = module.identifier();
						const lowerIdentifier = identifier.toLowerCase();
						let map = moduleWithoutCase.get(lowerIdentifier);
						if (map === undefined) {
							map = new Map();
							moduleWithoutCase.set(lowerIdentifier, map);
						}
						map.set(identifier, module);
					}
					for (const pair of moduleWithoutCase) {
						const map = pair[1];
						if (map.size > 1) {
							compilation.warnings.push(
								new CaseSensitiveModulesWarning(
									map.values(),
									compilation.moduleGraph
								)
							);
						}
					}
				});
			}
		);
	}
}

module.exports = WarnCaseSensitiveModulesPlugin;