webpack/lib/JavascriptMetaInfoPlugin.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 Sergey Melyukov @smelukov
*/

"use strict";

const {
	JAVASCRIPT_MODULE_TYPE_AUTO,
	JAVASCRIPT_MODULE_TYPE_DYNAMIC,
	JAVASCRIPT_MODULE_TYPE_ESM
} = require("./ModuleTypeConstants");
const InnerGraph = require("./optimize/InnerGraph");

/** @typedef {import("./Compiler")} Compiler */
/** @typedef {import("./Module").BuildInfo} BuildInfo */
/** @typedef {import("./javascript/JavascriptParser")} JavascriptParser */

const PLUGIN_NAME = "JavascriptMetaInfoPlugin";

class JavascriptMetaInfoPlugin {
	/**
	 * Apply the plugin
	 * @param {Compiler} compiler the compiler instance
	 * @returns {void}
	 */
	apply(compiler) {
		compiler.hooks.compilation.tap(
			PLUGIN_NAME,
			(compilation, { normalModuleFactory }) => {
				/**
				 * @param {JavascriptParser} parser the parser
				 * @returns {void}
				 */
				const handler = parser => {
					parser.hooks.call.for("eval").tap(PLUGIN_NAME, () => {
						const buildInfo =
							/** @type {BuildInfo} */
							(parser.state.module.buildInfo);
						buildInfo.moduleConcatenationBailout = "eval()";
						buildInfo.usingEval = true;
						const currentSymbol = InnerGraph.getTopLevelSymbol(parser.state);
						if (currentSymbol) {
							InnerGraph.addUsage(parser.state, null, currentSymbol);
						} else {
							InnerGraph.bailout(parser.state);
						}
					});
					parser.hooks.finish.tap(PLUGIN_NAME, () => {
						const buildInfo =
							/** @type {BuildInfo} */
							(parser.state.module.buildInfo);
						let topLevelDeclarations = buildInfo.topLevelDeclarations;
						if (topLevelDeclarations === undefined) {
							topLevelDeclarations = buildInfo.topLevelDeclarations = new Set();
						}
						for (const name of parser.scope.definitions.asSet()) {
							const freeInfo = parser.getFreeInfoFromVariable(name);
							if (freeInfo === undefined) {
								topLevelDeclarations.add(name);
							}
						}
					});
				};

				normalModuleFactory.hooks.parser
					.for(JAVASCRIPT_MODULE_TYPE_AUTO)
					.tap(PLUGIN_NAME, handler);
				normalModuleFactory.hooks.parser
					.for(JAVASCRIPT_MODULE_TYPE_DYNAMIC)
					.tap(PLUGIN_NAME, handler);
				normalModuleFactory.hooks.parser
					.for(JAVASCRIPT_MODULE_TYPE_ESM)
					.tap(PLUGIN_NAME, handler);
			}
		);
	}
}

module.exports = JavascriptMetaInfoPlugin;