webpack/lib/AutomaticPrefetchPlugin.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 asyncLib = require("neo-async");
const PrefetchDependency = require("./dependencies/PrefetchDependency");
const NormalModule = require("./NormalModule");

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

class AutomaticPrefetchPlugin {
	/**
	 * Apply the plugin
	 * @param {Compiler} compiler Webpack Compiler
	 * @returns {void}
	 */
	apply(compiler) {
		compiler.hooks.compilation.tap(
			"AutomaticPrefetchPlugin",
			(compilation, { normalModuleFactory }) => {
				compilation.dependencyFactories.set(
					PrefetchDependency,
					normalModuleFactory
				);
			}
		);
		let lastModules = null;
		compiler.hooks.afterCompile.tap("AutomaticPrefetchPlugin", compilation => {
			lastModules = compilation.modules
				.filter(m => m instanceof NormalModule)
				.map((/** @type {NormalModule} */ m) => ({
					context: m.context,
					request: m.request
				}));
		});
		compiler.hooks.make.tapAsync(
			"AutomaticPrefetchPlugin",
			(compilation, callback) => {
				if (!lastModules) return callback();
				asyncLib.forEach(
					lastModules,
					(m, callback) => {
						compilation.prefetch(
							m.context || compiler.context,
							new PrefetchDependency(m.request),
							callback
						);
					},
					callback
				);
			}
		);
	}
}
module.exports = AutomaticPrefetchPlugin;