webpack/lib/async-modules/AwaitDependenciesInitFragment.js

Packs CommonJs/AMD modules for the browser. Allows to split your codebase into multiple bundles, which can be loaded on demand. Support 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 InitFragment = require("../InitFragment");
const RuntimeGlobals = require("../RuntimeGlobals");

/** @typedef {import("webpack-sources").Source} Source */
/** @typedef {import("../Generator").GenerateContext} GenerateContext */

class AwaitDependenciesInitFragment extends InitFragment {
	/**
	 * @param {Set<string>} promises the promises that should be awaited
	 */
	constructor(promises) {
		super(
			undefined,
			InitFragment.STAGE_ASYNC_DEPENDENCIES,
			0,
			"await-dependencies"
		);
		this.promises = promises;
	}

	merge(other) {
		const promises = new Set(this.promises);
		for (const p of other.promises) {
			promises.add(p);
		}
		return new AwaitDependenciesInitFragment(promises);
	}

	/**
	 * @param {GenerateContext} generateContext context for generate
	 * @returns {string|Source} the source code that will be included as initialization code
	 */
	getContent({ runtimeRequirements }) {
		runtimeRequirements.add(RuntimeGlobals.module);
		const promises = this.promises;
		if (promises.size === 0) {
			return "";
		}
		if (promises.size === 1) {
			for (const p of promises) {
				return `${p} = await Promise.resolve(${p});\n`;
			}
		}
		const sepPromises = Array.from(promises).join(", ");
		return `([${sepPromises}] = await Promise.all([${sepPromises}]));\n`;
	}
}

module.exports = AwaitDependenciesInitFragment;