webpack/lib/loaders/LoaderOptionsPlugin.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 ModuleFilenameHelpers = require("../devtool/ModuleFilenameHelpers");
const NormalModule = require("../module/NormalModule");

/** @import Compiler from "../Compiler" */
/** @import { MatchObject } from "../devtool/ModuleFilenameHelpers" */

/**
 * @inline
 * @absolutePath true
 * @typedef {string} AbsolutePath
 */

/**
 * A configuration object that can be used to configure older loaders.
 * @additionalProperties
 * @inline
 * @typedef {object} LoaderOptionsPluginLoaderOptions
 * @property {AbsolutePath=} context The context that can be used to configure older loaders.
 */

/**
 * @additionalProperties
 * @schema plugins/LoaderOptionsPlugin
 * @typedef {object} LoaderOptionsPluginOptions
 * @property {boolean=} debug Whether loaders should be in debug mode or not. debug will be removed as of webpack 3.
 * @property {boolean=} minimize Where loaders can be switched to minimize mode.
 * @property {LoaderOptionsPluginLoaderOptions & Record<string, EXPECTED_ANY>=} options
 */

/**
 * Defines the loader context type used by this module.
 * @template T
 * @typedef {import("../module/NormalModule").LoaderContext<T>} LoaderContext
 */

const PLUGIN_NAME = "LoaderOptionsPlugin";

class LoaderOptionsPlugin {
	/**
	 * Creates an instance of LoaderOptionsPlugin.
	 * @param {LoaderOptionsPluginOptions & MatchObject & Record<string, EXPECTED_ANY>} options options object
	 */
	constructor(options = {}) {
		// If no options are set then generate empty options object
		if (typeof options !== "object") options = {};
		if (!options.test) {
			options.test = () => true;
		}
		/** @type {LoaderOptionsPluginOptions & MatchObject & Record<string, EXPECTED_ANY>} */
		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/LoaderOptionsPlugin.json"),
				this.options,
				{
					name: "Loader Options Plugin",
					baseDataPath: "options"
				},
				(options) =>
					require("../../schemas/plugins/LoaderOptionsPlugin.check")(options)
			);
		});

		compiler.hooks.compilation.tap(PLUGIN_NAME, (compilation) => {
			NormalModule.getCompilationHooks(compilation).loader.tap(
				PLUGIN_NAME,
				(context, module) => {
					const resource = module.resource;
					if (!resource) return;
					const i = resource.indexOf("?");
					if (
						ModuleFilenameHelpers.matchObject(
							this.options,
							i < 0 ? resource : resource.slice(0, i)
						)
					) {
						for (const key of Object.keys(this.options)) {
							if (key === "include" || key === "exclude" || key === "test") {
								continue;
							}

							/** @type {LoaderContext<EXPECTED_ANY> & Record<string, EXPECTED_ANY>} */
							(context)[key] = this.options[key];
						}
					}
				}
			);
		});
	}
}

module.exports = LoaderOptionsPlugin;