webpack/lib/EvalDevToolModulePlugin.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 { ConcatSource, RawSource } = require("webpack-sources");
const ExternalModule = require("./ExternalModule");
const ModuleFilenameHelpers = require("./ModuleFilenameHelpers");
const JavascriptModulesPlugin = require("./javascript/JavascriptModulesPlugin");

/** @typedef {import("webpack-sources").Source} Source */
/** @typedef {import("./Compiler")} Compiler */

/** @type {WeakMap<Source, Source>} */
const cache = new WeakMap();

const devtoolWarning = new RawSource(`/*
 * ATTENTION: The "eval" devtool has been used (maybe by default in mode: "development").
 * This devtool is neither made for production nor for readable output files.
 * It uses "eval()" calls to create a separate source file in the browser devtools.
 * If you are trying to read the output file, select a different devtool (https://webpack.js.org/configuration/devtool/)
 * or disable the default devtool with "devtool: false".
 * If you are looking for production-ready output files, see mode: "production" (https://webpack.js.org/configuration/mode/).
 */
`);

class EvalDevToolModulePlugin {
	constructor(options) {
		this.namespace = options.namespace || "";
		this.sourceUrlComment = options.sourceUrlComment || "\n//# sourceURL=[url]";
		this.moduleFilenameTemplate =
			options.moduleFilenameTemplate ||
			"webpack://[namespace]/[resourcePath]?[loaders]";
	}

	/**
	 * Apply the plugin
	 * @param {Compiler} compiler the compiler instance
	 * @returns {void}
	 */
	apply(compiler) {
		compiler.hooks.compilation.tap("EvalDevToolModulePlugin", compilation => {
			const hooks = JavascriptModulesPlugin.getCompilationHooks(compilation);
			hooks.renderModuleContent.tap(
				"EvalDevToolModulePlugin",
				(source, module, { runtimeTemplate, chunkGraph }) => {
					const cacheEntry = cache.get(source);
					if (cacheEntry !== undefined) return cacheEntry;
					if (module instanceof ExternalModule) {
						cache.set(source, source);
						return source;
					}
					const content = source.source();
					const str = ModuleFilenameHelpers.createFilename(
						module,
						{
							moduleFilenameTemplate: this.moduleFilenameTemplate,
							namespace: this.namespace
						},
						{
							requestShortener: runtimeTemplate.requestShortener,
							chunkGraph,
							hashFunction: compilation.outputOptions.hashFunction
						}
					);
					const footer =
						"\n" +
						this.sourceUrlComment.replace(
							/\[url\]/g,
							encodeURI(str)
								.replace(/%2F/g, "/")
								.replace(/%20/g, "_")
								.replace(/%5E/g, "^")
								.replace(/%5C/g, "\\")
								.replace(/^\//, "")
						);
					const result = new RawSource(
						`eval(${JSON.stringify(content + footer)});`
					);
					cache.set(source, result);
					return result;
				}
			);
			hooks.inlineInRuntimeBailout.tap(
				"EvalDevToolModulePlugin",
				() => "the eval devtool is used."
			);
			hooks.render.tap(
				"EvalDevToolModulePlugin",
				source => new ConcatSource(devtoolWarning, source)
			);
			hooks.chunkHash.tap("EvalDevToolModulePlugin", (chunk, hash) => {
				hash.update("EvalDevToolModulePlugin");
				hash.update("2");
			});
		});
	}
}

module.exports = EvalDevToolModulePlugin;