webpack/lib/NormalModuleReplacementPlugin.js

Packs CommonJs/AMD modules for the browser. Allows to split your codebase into multiple bundles, which can be loaded on demand. Support 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 { join, dirname } = require("./util/fs");

/** @typedef {import("./Compiler")} Compiler */
/** @typedef {function(TODO): void} ModuleReplacer */

class NormalModuleReplacementPlugin {
	/**
	 * Create an instance of the plugin
	 * @param {RegExp} resourceRegExp the resource matcher
	 * @param {string|ModuleReplacer} newResource the resource replacement
	 */
	constructor(resourceRegExp, newResource) {
		this.resourceRegExp = resourceRegExp;
		this.newResource = newResource;
	}

	/**
	 * Apply the plugin
	 * @param {Compiler} compiler the compiler instance
	 * @returns {void}
	 */
	apply(compiler) {
		const resourceRegExp = this.resourceRegExp;
		const newResource = this.newResource;
		compiler.hooks.normalModuleFactory.tap(
			"NormalModuleReplacementPlugin",
			nmf => {
				nmf.hooks.beforeResolve.tap("NormalModuleReplacementPlugin", result => {
					if (resourceRegExp.test(result.request)) {
						if (typeof newResource === "function") {
							newResource(result);
						} else {
							result.request = newResource;
						}
					}
				});
				nmf.hooks.afterResolve.tap("NormalModuleReplacementPlugin", result => {
					const createData = result.createData;
					if (resourceRegExp.test(createData.resource)) {
						if (typeof newResource === "function") {
							newResource(result);
						} else {
							const fs = compiler.inputFileSystem;
							if (
								newResource.startsWith("/") ||
								(newResource.length > 1 && newResource[1] === ":")
							) {
								createData.resource = newResource;
							} else {
								createData.resource = join(
									fs,
									dirname(fs, createData.resource),
									newResource
								);
							}
						}
					}
				});
			}
		);
	}
}

module.exports = NormalModuleReplacementPlugin;