webpack/lib/dependencies/ImportMetaContextPlugin.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 Ivan Kopeykin @vankop
*/

"use strict";

const {
	JAVASCRIPT_MODULE_TYPE_AUTO,
	JAVASCRIPT_MODULE_TYPE_ESM
} = require("../ModuleTypeConstants");
const ContextElementDependency = require("./ContextElementDependency");
const ImportMetaContextDependency = require("./ImportMetaContextDependency");
const ImportMetaContextDependencyParserPlugin = require("./ImportMetaContextDependencyParserPlugin");
const ImportMetaGlobDependency = require("./ImportMetaGlobDependency");
const ImportMetaGlobDependencyParserPlugin = require("./ImportMetaGlobDependencyParserPlugin");
const { isImportMetaFieldEnabled } = require("./ImportMetaPlugin");

/** @typedef {import("../../declarations/WebpackOptions").JavascriptParserOptions} JavascriptParserOptions */
/** @typedef {import("../Compiler")} Compiler */
/** @typedef {import("../javascript/JavascriptParser")} Parser */

const PLUGIN_NAME = "ImportMetaContextPlugin";

/** @type {(parserOptions: JavascriptParserOptions) => boolean} */
const isImportMetaContextEnabled = (parserOptions) => {
	const importMeta = parserOptions.importMeta;
	if (
		Boolean(importMeta) &&
		typeof importMeta === "object" &&
		Object.prototype.hasOwnProperty.call(importMeta, "webpackContext")
	) {
		return isImportMetaFieldEnabled(importMeta, "webpackContext");
	}
	if (parserOptions.importMetaContext === false) {
		return false;
	}
	return isImportMetaFieldEnabled(importMeta, "webpackContext");
};

// Gated only by the `importMeta.glob` field — independent of the legacy
// `importMetaContext` toggle, which controls `import.meta.webpackContext`.
/** @type {(parserOptions: JavascriptParserOptions) => boolean} */
const isImportMetaGlobEnabled = (parserOptions) =>
	isImportMetaFieldEnabled(parserOptions.importMeta, "glob");

class ImportMetaContextPlugin {
	/**
	 * Applies the plugin by registering its hooks on the compiler.
	 * @param {Compiler} compiler the compiler instance
	 * @returns {void}
	 */
	apply(compiler) {
		compiler.hooks.compilation.tap(
			PLUGIN_NAME,
			(compilation, { contextModuleFactory, normalModuleFactory }) => {
				compilation.dependencyFactories.set(
					ImportMetaContextDependency,
					contextModuleFactory
				);
				compilation.dependencyTemplates.set(
					ImportMetaContextDependency,
					new ImportMetaContextDependency.Template()
				);
				compilation.dependencyFactories.set(
					ImportMetaGlobDependency,
					contextModuleFactory
				);
				compilation.dependencyTemplates.set(
					ImportMetaGlobDependency,
					new ImportMetaGlobDependency.Template()
				);
				compilation.dependencyFactories.set(
					ContextElementDependency,
					normalModuleFactory
				);

				/**
				 * Handles the hook callback for this code path.
				 * @param {Parser} parser parser parser
				 * @param {JavascriptParserOptions} parserOptions parserOptions
				 * @returns {void}
				 */
				const handler = (parser, parserOptions) => {
					if (isImportMetaContextEnabled(parserOptions)) {
						new ImportMetaContextDependencyParserPlugin().apply(parser);
					}
					if (isImportMetaGlobEnabled(parserOptions)) {
						new ImportMetaGlobDependencyParserPlugin().apply(parser);
					}
				};

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

module.exports = ImportMetaContextPlugin;