package.lib.dependencies.ImportMetaPlugin.js Maven / Gradle / Ivy

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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.
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/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Ivan Kopeykin @vankop
*/

"use strict";

const { pathToFileURL } = require("url");
const ModuleDependencyWarning = require("../ModuleDependencyWarning");
const {
	JAVASCRIPT_MODULE_TYPE_AUTO,
	JAVASCRIPT_MODULE_TYPE_ESM
} = require("../ModuleTypeConstants");
const Template = require("../Template");
const BasicEvaluatedExpression = require("../javascript/BasicEvaluatedExpression");
const {
	evaluateToIdentifier,
	toConstantDependency,
	evaluateToString,
	evaluateToNumber
} = require("../javascript/JavascriptParserHelpers");
const memoize = require("../util/memoize");
const propertyAccess = require("../util/propertyAccess");
const ConstDependency = require("./ConstDependency");

/** @typedef {import("estree").MemberExpression} MemberExpression */
/** @typedef {import("../../declarations/WebpackOptions").JavascriptParserOptions} JavascriptParserOptions */
/** @typedef {import("../Compiler")} Compiler */
/** @typedef {import("../Dependency").DependencyLocation} DependencyLocation */
/** @typedef {import("../NormalModule")} NormalModule */
/** @typedef {import("../javascript/JavascriptParser")} Parser */
/** @typedef {import("../javascript/JavascriptParser").Range} Range */

const getCriticalDependencyWarning = memoize(() =>
	require("./CriticalDependencyWarning")
);

const PLUGIN_NAME = "ImportMetaPlugin";

class ImportMetaPlugin {
	/**
	 * @param {Compiler} compiler compiler
	 */
	apply(compiler) {
		compiler.hooks.compilation.tap(
			PLUGIN_NAME,
			(compilation, { normalModuleFactory }) => {
				/**
				 * @param {NormalModule} module module
				 * @returns {string} file url
				 */
				const getUrl = module => {
					return pathToFileURL(module.resource).toString();
				};
				/**
				 * @param {Parser} parser parser parser
				 * @param {JavascriptParserOptions} parserOptions parserOptions
				 * @returns {void}
				 */
				const parserHandler = (parser, { importMeta }) => {
					if (importMeta === false) {
						const { importMetaName } = compilation.outputOptions;
						if (importMetaName === "import.meta") return;

						parser.hooks.expression
							.for("import.meta")
							.tap(PLUGIN_NAME, metaProperty => {
								const dep = new ConstDependency(
									/** @type {string} */ (importMetaName),
									/** @type {Range} */ (metaProperty.range)
								);
								dep.loc = /** @type {DependencyLocation} */ (metaProperty.loc);
								parser.state.module.addPresentationalDependency(dep);
								return true;
							});
						return;
					}

					/// import.meta direct ///
					const webpackVersion = parseInt(
						require("../../package.json").version,
						10
					);
					const importMetaUrl = () =>
						JSON.stringify(getUrl(parser.state.module));
					const importMetaWebpackVersion = () => JSON.stringify(webpackVersion);
					/**
					 * @param {string[]} members members
					 * @returns {string} error message
					 */
					const importMetaUnknownProperty = members =>
						`${Template.toNormalComment(
							"unsupported import.meta." + members.join(".")
						)} undefined${propertyAccess(members, 1)}`;
					parser.hooks.typeof
						.for("import.meta")
						.tap(
							PLUGIN_NAME,
							toConstantDependency(parser, JSON.stringify("object"))
						);
					parser.hooks.expression
						.for("import.meta")
						.tap(PLUGIN_NAME, metaProperty => {
							const referencedPropertiesInDestructuring =
								parser.destructuringAssignmentPropertiesFor(metaProperty);
							if (!referencedPropertiesInDestructuring) {
								const CriticalDependencyWarning =
									getCriticalDependencyWarning();
								parser.state.module.addWarning(
									new ModuleDependencyWarning(
										parser.state.module,
										new CriticalDependencyWarning(
											"Accessing import.meta directly is unsupported (only property access or destructuring is supported)"
										),
										/** @type {DependencyLocation} */ (metaProperty.loc)
									)
								);
								const dep = new ConstDependency(
									`${
										parser.isAsiPosition(
											/** @type {Range} */ (metaProperty.range)[0]
										)
											? ";"
											: ""
									}({})`,
									/** @type {Range} */ (metaProperty.range)
								);
								dep.loc = /** @type {DependencyLocation} */ (metaProperty.loc);
								parser.state.module.addPresentationalDependency(dep);
								return true;
							}

							let str = "";
							for (const { id: prop } of referencedPropertiesInDestructuring) {
								switch (prop) {
									case "url":
										str += `url: ${importMetaUrl()},`;
										break;
									case "webpack":
										str += `webpack: ${importMetaWebpackVersion()},`;
										break;
									default:
										str += `[${JSON.stringify(
											prop
										)}]: ${importMetaUnknownProperty([prop])},`;
										break;
								}
							}
							const dep = new ConstDependency(
								`({${str}})`,
								/** @type {Range} */ (metaProperty.range)
							);
							dep.loc = /** @type {DependencyLocation} */ (metaProperty.loc);
							parser.state.module.addPresentationalDependency(dep);
							return true;
						});
					parser.hooks.evaluateTypeof
						.for("import.meta")
						.tap(PLUGIN_NAME, evaluateToString("object"));
					parser.hooks.evaluateIdentifier.for("import.meta").tap(
						PLUGIN_NAME,
						evaluateToIdentifier("import.meta", "import.meta", () => [], true)
					);

					/// import.meta.url ///
					parser.hooks.typeof
						.for("import.meta.url")
						.tap(
							PLUGIN_NAME,
							toConstantDependency(parser, JSON.stringify("string"))
						);
					parser.hooks.expression
						.for("import.meta.url")
						.tap(PLUGIN_NAME, expr => {
							const dep = new ConstDependency(
								importMetaUrl(),
								/** @type {Range} */ (expr.range)
							);
							dep.loc = /** @type {DependencyLocation} */ (expr.loc);
							parser.state.module.addPresentationalDependency(dep);
							return true;
						});
					parser.hooks.evaluateTypeof
						.for("import.meta.url")
						.tap(PLUGIN_NAME, evaluateToString("string"));
					parser.hooks.evaluateIdentifier
						.for("import.meta.url")
						.tap(PLUGIN_NAME, expr => {
							return new BasicEvaluatedExpression()
								.setString(getUrl(parser.state.module))
								.setRange(/** @type {Range} */ (expr.range));
						});

					/// import.meta.webpack ///
					parser.hooks.typeof
						.for("import.meta.webpack")
						.tap(
							PLUGIN_NAME,
							toConstantDependency(parser, JSON.stringify("number"))
						);
					parser.hooks.expression
						.for("import.meta.webpack")
						.tap(
							PLUGIN_NAME,
							toConstantDependency(parser, importMetaWebpackVersion())
						);
					parser.hooks.evaluateTypeof
						.for("import.meta.webpack")
						.tap(PLUGIN_NAME, evaluateToString("number"));
					parser.hooks.evaluateIdentifier
						.for("import.meta.webpack")
						.tap(PLUGIN_NAME, evaluateToNumber(webpackVersion));

					/// Unknown properties ///
					parser.hooks.unhandledExpressionMemberChain
						.for("import.meta")
						.tap(PLUGIN_NAME, (expr, members) => {
							const dep = new ConstDependency(
								importMetaUnknownProperty(members),
								/** @type {Range} */ (expr.range)
							);
							dep.loc = /** @type {DependencyLocation} */ (expr.loc);
							parser.state.module.addPresentationalDependency(dep);
							return true;
						});
					parser.hooks.evaluate
						.for("MemberExpression")
						.tap(PLUGIN_NAME, expression => {
							const expr = /** @type {MemberExpression} */ (expression);
							if (
								expr.object.type === "MetaProperty" &&
								expr.object.meta.name === "import" &&
								expr.object.property.name === "meta" &&
								expr.property.type ===
									(expr.computed ? "Literal" : "Identifier")
							) {
								return new BasicEvaluatedExpression()
									.setUndefined()
									.setRange(/** @type {Range} */ (expr.range));
							}
						});
				};

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

module.exports = ImportMetaPlugin;