webpack/lib/async-modules/isGeneratorLowered.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
*/

"use strict";

/** @typedef {import("../Module")} Module */
/** @typedef {import("../ModuleGraph")} ModuleGraph */
/** @typedef {import("../RuntimeTemplate")} RuntimeTemplate */

/**
 * Whether an async module is lowered to a generator: the target has no
 * `async`/`await` but supports generators, and the module contains no
 * top-level `for await…of` (which generators can't express).
 * @param {Module} module module
 * @param {ModuleGraph} moduleGraph module graph
 * @param {RuntimeTemplate} runtimeTemplate runtime template
 * @returns {boolean} true when the module should be emitted as a generator
 */
const isGeneratorLowered = (module, moduleGraph, runtimeTemplate) =>
	moduleGraph.isAsync(module) &&
	!runtimeTemplate.supportsAsyncFunction() &&
	Boolean(runtimeTemplate.supportsGenerator()) &&
	!(module.buildInfo && module.buildInfo.usesTopLevelAwaitForOf);

module.exports = isGeneratorLowered;