source: frontend/node_modules/webpack/lib/dependencies/RequireEnsurePlugin.js

/*
        MIT License http://www.opensource.org/licenses/mit-license.php
        Author Tobias Koppers @sokra
*/

"use strict";

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

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

const PLUGIN_NAME = "RequireEnsurePlugin";

class RequireEnsurePlugin {
        /**
         * Applies the plugin by registering its hooks on the compiler.
         * @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()
                                );

                                /**
                                 * Handles the hook callback for this code path.
                                 * @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;