webpack/lib/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("./ModuleFilenameHelpers");
const NormalModule = require("./NormalModule");
const createSchemaValidation = require("./util/create-schema-validation");

/** @typedef {import("../declarations/plugins/LoaderOptionsPlugin").LoaderOptionsPluginOptions} LoaderOptionsPluginOptions */
/** @typedef {import("./Compiler")} Compiler */
/** @typedef {import("./ModuleFilenameHelpers").MatchObject} MatchObject  */

const validate = createSchemaValidation(
	require("../schemas/plugins/LoaderOptionsPlugin.check.js"),
	() => require("../schemas/plugins/LoaderOptionsPlugin.json"),
	{
		name: "Loader Options Plugin",
		baseDataPath: "options"
	}
);

class LoaderOptionsPlugin {
	/**
	 * @param {LoaderOptionsPluginOptions & MatchObject} options options object
	 */
	constructor(options = {}) {
		validate(options);
		// If no options are set then generate empty options object
		if (typeof options !== "object") options = {};
		if (!options.test) {
			// This is mocking a RegExp object which always returns true
			// TODO: Figure out how to do `as unknown as RegExp` for this line
			// in JSDoc equivalent
			/** @type {any} */
			const defaultTrueMockRegExp = {
				test: () => true
			};

			/** @type {RegExp} */
			options.test = defaultTrueMockRegExp;
		}
		this.options = options;
	}

	/**
	 * Apply the plugin
	 * @param {Compiler} compiler the compiler instance
	 * @returns {void}
	 */
	apply(compiler) {
		const options = this.options;
		compiler.hooks.compilation.tap("LoaderOptionsPlugin", compilation => {
			NormalModule.getCompilationHooks(compilation).loader.tap(
				"LoaderOptionsPlugin",
				(context, module) => {
					const resource = module.resource;
					if (!resource) return;
					const i = resource.indexOf("?");
					if (
						ModuleFilenameHelpers.matchObject(
							options,
							i < 0 ? resource : resource.slice(0, i)
						)
					) {
						for (const key of Object.keys(options)) {
							if (key === "include" || key === "exclude" || key === "test") {
								continue;
							}
							context[key] = options[key];
						}
					}
				}
			);
		});
	}
}

module.exports = LoaderOptionsPlugin;