webpack/lib/async-modules/AsyncModuleHelpers.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 Haijie Xie @hai-x
*/

"use strict";

const HarmonyImportDependency = require("../dependencies/HarmonyImportDependency");

/** @import ModuleGraph from "../ModuleGraph" */
/** @import Module from "../Module" */

/** @typedef {Set<Module>} Modules */

/**
 * Gets outgoing async modules.
 * @param {ModuleGraph} moduleGraph module graph
 * @param {Module} module module
 * @returns {Modules} set of modules
 */
const getOutgoingAsyncModules = (moduleGraph, module) => {
	/** @type {Modules} */
	const set = new Set();
	/** @type {Modules} */
	const seen = new Set();
	(function g(module) {
		if (!moduleGraph.isAsync(module) || seen.has(module)) return;
		seen.add(module);
		if (module.buildMeta && module.buildMeta.async) {
			set.add(module);
		} else {
			const outgoingConnectionMap =
				moduleGraph.getOutgoingConnectionsByModule(module);
			if (outgoingConnectionMap) {
				// Walk the imports in source order: the spec gathers these from
				// `[[RequestedModules]]`, and their evaluation order is observable.
				for (const dependency of module.dependencies) {
					if (!(dependency instanceof HarmonyImportDependency)) continue;
					const referenced = moduleGraph.getModule(dependency);
					if (!referenced || seen.has(referenced)) continue;
					const connections = outgoingConnectionMap.get(referenced);
					if (
						connections &&
						connections.some(
							(c) =>
								c.dependency instanceof HarmonyImportDependency &&
								c.isTargetActive(undefined)
						)
					) {
						g(referenced);
					}
				}
			}
		}
	})(module);
	return set;
};

module.exports.getOutgoingAsyncModules = getOutgoingAsyncModules;