webpack/lib/async-modules/InferAsyncModulesPlugin.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 Tobias Koppers @sokra
*/

"use strict";

const isDependencyKind = require("../graph/isDependencyKind");

/** @import Compiler from "../Compiler" */
/** @import Module, { BuildMeta } from "../module/Module" */

const PLUGIN_NAME = "InferAsyncModulesPlugin";

class InferAsyncModulesPlugin {
	/**
	 * 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) => {
			const { moduleGraph } = compilation;
			compilation.hooks.finishModules.tap(PLUGIN_NAME, (modules) => {
				/** @type {Set<Module>} */
				const queue = new Set();
				for (const module of modules) {
					if (module.buildMeta && module.buildMeta.async) {
						queue.add(module);
					}
				}
				for (const module of queue) {
					moduleGraph.setAsync(module);
					for (const [
						originModule,
						connections
					] of moduleGraph.getIncomingConnectionsByOriginModule(module)) {
						if (
							connections.some(
								(c) =>
									c.dependency !== null &&
									(isDependencyKind(c.dependency, "esm-import") ||
										// only an ESM module has the async wrapper to await it in
										(isDependencyKind(c.dependency, "provided") &&
											/** @type {BuildMeta} */
											(/** @type {Module} */ (originModule).buildMeta)
												.exportsType === "namespace")) &&
									c.isTargetActive(undefined)
							)
						) {
							queue.add(/** @type {Module} */ (originModule));
						}
					}
				}
			});
		});
	}
}

module.exports = InferAsyncModulesPlugin;