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

"use strict";

const InnerGraph = require("./optimize/InnerGraph");

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

class JavascriptMetaInfoPlugin {
	/**
	 * Apply the plugin
	 * @param {Compiler} compiler the compiler instance
	 * @returns {void}
	 */
	apply(compiler) {
		compiler.hooks.compilation.tap(
			"JavascriptMetaInfoPlugin",
			(compilation, { normalModuleFactory }) => {
				/**
				 * @param {JavascriptParser} parser the parser
				 * @returns {void}
				 */
				const handler = parser => {
					parser.hooks.call.for("eval").tap("JavascriptMetaInfoPlugin", () => {
						parser.state.module.buildInfo.moduleConcatenationBailout = "eval()";
						parser.state.module.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("JavascriptMetaInfoPlugin", () => {
						let topLevelDeclarations =
							parser.state.module.buildInfo.topLevelDeclarations;
						if (topLevelDeclarations === undefined) {
							topLevelDeclarations =
								parser.state.module.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/auto")
					.tap("JavascriptMetaInfoPlugin", handler);
				normalModuleFactory.hooks.parser
					.for("javascript/dynamic")
					.tap("JavascriptMetaInfoPlugin", handler);
				normalModuleFactory.hooks.parser
					.for("javascript/esm")
					.tap("JavascriptMetaInfoPlugin", handler);
			}
		);
	}
}

module.exports = JavascriptMetaInfoPlugin;