webpack/lib/dependencies/RequireEnsurePlugin.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 Tobias Koppers @sokra
*/

"use strict";

const RequireEnsureDependency = require("./RequireEnsureDependency");
const RequireEnsureItemDependency = require("./RequireEnsureItemDependency");

const RequireEnsureDependenciesBlockParserPlugin = require("./RequireEnsureDependenciesBlockParserPlugin");

const {
	JAVASCRIPT_MODULE_TYPE_AUTO,
	JAVASCRIPT_MODULE_TYPE_DYNAMIC
} = require("../ModuleTypeConstants");
const {
	evaluateToString,
	toConstantDependency
} = require("../javascript/JavascriptParserHelpers");

/** @typedef {import("../../declarations/WebpackOptions").JavascriptParserOptions} JavascriptParserOptions */
/** @typedef {import("../Compiler")} Compiler */
/** @typedef {import("../javascript/JavascriptParser")} Parser */

const PLUGIN_NAME = "RequireEnsurePlugin";

class RequireEnsurePlugin {
	/**
	 * Apply the plugin
	 * @param {Compiler} compiler the compiler instance
	 * @returns {void}
	 */
	apply(compiler) {
		compiler.hooks.compilation.tap(
			PLUGIN_NAME,
			(compilation, { normalModuleFactory }) => {
				compilation.dependencyFactories.set(
					RequireEnsureItemDependency,
					normalModuleFactory
				);
				compilation.dependencyTemplates.set(
					RequireEnsureItemDependency,
					new RequireEnsureItemDependency.Template()
				);

				compilation.dependencyTemplates.set(
					RequireEnsureDependency,
					new RequireEnsureDependency.Template()
				);

				/**
				 * @param {Parser} parser parser parser
				 * @param {JavascriptParserOptions} parserOptions parserOptions
				 * @returns {void}
				 */
				const handler = (parser, parserOptions) => {
					if (
						parserOptions.requireEnsure !== undefined &&
						!parserOptions.requireEnsure
					)
						return;

					new RequireEnsureDependenciesBlockParserPlugin().apply(parser);
					parser.hooks.evaluateTypeof
						.for("require.ensure")
						.tap(PLUGIN_NAME, evaluateToString("function"));
					parser.hooks.typeof
						.for("require.ensure")
						.tap(
							PLUGIN_NAME,
							toConstantDependency(parser, JSON.stringify("function"))
						);
				};

				normalModuleFactory.hooks.parser
					.for(JAVASCRIPT_MODULE_TYPE_AUTO)
					.tap(PLUGIN_NAME, handler);
				normalModuleFactory.hooks.parser
					.for(JAVASCRIPT_MODULE_TYPE_DYNAMIC)
					.tap(PLUGIN_NAME, handler);
			}
		);
	}
}
module.exports = RequireEnsurePlugin;