webpack/lib/runtime/CompatGetDefaultExportRuntimeModule.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";

const RuntimeGlobals = require("../RuntimeGlobals");
const Template = require("../Template");
const HelperRuntimeModule = require("./HelperRuntimeModule");

/** @typedef {import("../Compilation")} Compilation */

class CompatGetDefaultExportRuntimeModule extends HelperRuntimeModule {
	constructor() {
		super("compat get default export");
	}

	/**
	 * @returns {string | null} runtime code
	 */
	generate() {
		const compilation = /** @type {Compilation} */ (this.compilation);
		const { runtimeTemplate } = compilation;
		const fn = RuntimeGlobals.compatGetDefaultExport;
		return Template.asString([
			"// getDefaultExport function for compatibility with non-harmony modules",
			`${fn} = ${runtimeTemplate.basicFunction("module", [
				"var getter = module && module.__esModule ?",
				Template.indent([
					`${runtimeTemplate.returningFunction("module['default']")} :`,
					`${runtimeTemplate.returningFunction("module")};`
				]),
				`${RuntimeGlobals.definePropertyGetters}(getter, { a: getter });`,
				"return getter;"
			])};`
		]);
	}
}

module.exports = CompatGetDefaultExportRuntimeModule;