webpack/lib/WarnCaseSensitiveModulesPlugin.js

/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Tobias Koppers @sokra
*/

"use strict";

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

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

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", () => {
					const moduleWithoutCase = new Map();
					for (const module of compilation.modules) {
						const identifier = module.identifier().toLowerCase();
						const array = moduleWithoutCase.get(identifier);
						if (array) {
							array.push(module);
						} else {
							moduleWithoutCase.set(identifier, [module]);
						}
					}
					for (const pair of moduleWithoutCase) {
						const array = pair[1];
						if (array.length > 1) {
							compilation.warnings.push(
								new CaseSensitiveModulesWarning(array, compilation.moduleGraph)
							);
						}
					}
				});
			}
		);
	}
}

module.exports = WarnCaseSensitiveModulesPlugin;