webpack/lib/dll/DllPlugin.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 FlagAllModulesAsUsedPlugin = require("../optimize/FlagAllModulesAsUsedPlugin");
const DllEntryPlugin = require("./DllEntryPlugin");
const LibManifestPlugin = require("./LibManifestPlugin");

/** @import Compiler from "../Compiler" */
/** @import { Entries, Options } from "./DllEntryPlugin" */

/**
 * @inline
 * @minLength 1
 * @typedef {string} NonEmptyString
 */

/**
 * @schema plugins/dll/DllPlugin
 * @typedef {object} DllPluginOptions
 * @property {NonEmptyString=} context Context of requests in the manifest file (defaults to the webpack context).
 * @property {boolean=} entryOnly If true, only entry points will be exposed (default: true).
 * @property {boolean=} format If true, manifest json file (output) will be formatted.
 * @property {NonEmptyString=} name Name of the exposed dll function (external name, use value of 'output.library').
 * @property {NonEmptyString} path Absolute path to the manifest json file (output).
 * @property {NonEmptyString=} type Type of the dll bundle (external type, use value of 'output.libraryTarget').
 */

const PLUGIN_NAME = "DllPlugin";

class DllPlugin {
	/**
	 * Creates an instance of DllPlugin.
	 * @param {DllPluginOptions} options options object
	 */
	constructor(options) {
		/** @type {DllPluginOptions} */
		this.options = options;
	}

	/**
	 * Applies the plugin by registering its hooks on the compiler.
	 * @param {Compiler} compiler the compiler instance
	 * @returns {void}
	 */
	apply(compiler) {
		compiler.hooks.validate.tap(PLUGIN_NAME, () => {
			compiler.validate(
				() => require("../../schemas/plugins/dll/DllPlugin.json"),
				this.options,
				{
					name: "Dll Plugin",
					baseDataPath: "options"
				},
				(options) =>
					require("../../schemas/plugins/dll/DllPlugin.check")(options)
			);
		});

		const entryOnly = this.options.entryOnly !== false;
		compiler.hooks.entryOption.tap(PLUGIN_NAME, (context, entry) => {
			if (typeof entry !== "function") {
				for (const name of Object.keys(entry)) {
					/** @type {Options} */
					const options = { name };
					new DllEntryPlugin(
						context,
						/** @type {Entries} */
						(entry[name].import),
						options
					).apply(compiler);
				}
			} else {
				throw new Error(
					`${PLUGIN_NAME} doesn't support dynamic entry (function) yet`
				);
			}
			return true;
		});
		new LibManifestPlugin({ ...this.options, entryOnly }).apply(compiler);
		if (!entryOnly) {
			new FlagAllModulesAsUsedPlugin(PLUGIN_NAME).apply(compiler);
			compiler.hooks.compilation.tap(
				PLUGIN_NAME,
				(_compilation, { normalModuleFactory }) => {
					normalModuleFactory.hooks.module.tap(
						{ name: PLUGIN_NAME, stage: 10 },
						(module) => {
							if (module.factoryMeta === undefined) {
								module.factoryMeta = {};
							}
							module.factoryMeta.sideEffectFree = false;
							return module;
						}
					);
				}
			);
		}
	}
}

module.exports = DllPlugin;