webpack/lib/ids/HashedModuleIdsPlugin.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 {
	compareModulesByPreOrderIndexOrIdentifier
} = require("../util/comparators");
const createSchemaValidation = require("../util/create-schema-validation");
const createHash = require("../util/createHash");
const {
	getUsedModuleIdsAndModules,
	getFullModuleName
} = require("./IdHelpers");

/** @typedef {import("../../declarations/plugins/HashedModuleIdsPlugin").HashedModuleIdsPluginOptions} HashedModuleIdsPluginOptions */
/** @typedef {import("../Compiler")} Compiler */

const validate = createSchemaValidation(
	require("../../schemas/plugins/HashedModuleIdsPlugin.check.js"),
	() => require("../../schemas/plugins/HashedModuleIdsPlugin.json"),
	{
		name: "Hashed Module Ids Plugin",
		baseDataPath: "options"
	}
);

class HashedModuleIdsPlugin {
	/**
	 * @param {HashedModuleIdsPluginOptions=} options options object
	 */
	constructor(options = {}) {
		validate(options);

		/** @type {HashedModuleIdsPluginOptions} */
		this.options = {
			context: undefined,
			hashFunction: "md4",
			hashDigest: "base64",
			hashDigestLength: 4,
			...options
		};
	}

	/**
	 * Apply the plugin
	 * @param {Compiler} compiler the compiler instance
	 * @returns {void}
	 */
	apply(compiler) {
		const options = this.options;
		compiler.hooks.compilation.tap("HashedModuleIdsPlugin", compilation => {
			compilation.hooks.moduleIds.tap("HashedModuleIdsPlugin", () => {
				const chunkGraph = compilation.chunkGraph;
				const context = this.options.context
					? this.options.context
					: compiler.context;

				const [usedIds, modules] = getUsedModuleIdsAndModules(compilation);
				const modulesInNaturalOrder = modules.sort(
					compareModulesByPreOrderIndexOrIdentifier(compilation.moduleGraph)
				);
				for (const module of modulesInNaturalOrder) {
					const ident = getFullModuleName(module, context, compiler.root);
					const hash = createHash(options.hashFunction);
					hash.update(ident || "");
					const hashId = /** @type {string} */ (
						hash.digest(options.hashDigest)
					);
					let len = options.hashDigestLength;
					while (usedIds.has(hashId.slice(0, len)))
						/** @type {number} */ (len)++;
					const moduleId = hashId.slice(0, len);
					chunkGraph.setModuleId(module, moduleId);
					usedIds.add(moduleId);
				}
			});
		});
	}
}

module.exports = HashedModuleIdsPlugin;