webpack/lib/WarnCaseSensitiveModulesPlugin.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 Tobias Koppers @sokra
*/

"use strict";

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

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

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();

						// Ignore `data:` URLs, because it's not a real path
						if (
							/** @type {NormalModule} */
							(module).resourceResolveData !== undefined &&
							/** @type {NormalModule} */
							(module).resourceResolveData.encodedContent !== undefined
						) {
							continue;
						}

						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;