source: frontend/node_modules/webpack/lib/runtime/CreateFakeNamespaceObjectRuntimeModule.js

/*
        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 CreateFakeNamespaceObjectRuntimeModule extends HelperRuntimeModule {
        constructor() {
                super("create fake namespace object");
        }

        /**
         * Generates runtime code for this runtime module.
         * @returns {string | null} runtime code
         */
        generate() {
                const compilation = /** @type {Compilation} */ (this.compilation);
                const { runtimeTemplate } = compilation;
                const fn = RuntimeGlobals.createFakeNamespaceObject;
                return Template.asString([
                        `var getProto = Object.getPrototypeOf ? ${runtimeTemplate.returningFunction(
                                "Object.getPrototypeOf(obj)",
                                "obj"
                        )} : ${runtimeTemplate.returningFunction("obj.__proto__", "obj")};`,
                        "var leafPrototypes;",
                        "// create a fake namespace object",
                        "// mode & 1: value is a module id, require it",
                        "// mode & 2: merge all properties of value into the ns",
                        "// mode & 4: return value when already ns object",
                        "// mode & 16: return value when it's Promise-like",
                        "// mode & 8|1: behave like require",
                        // Note: must be a function (not arrow), because this is used in body!
                        `${fn} = function(value, mode) {`,
                        Template.indent([
                                "if(mode & 1) value = this(value);",
                                "if(mode & 8) return value;",
                                "if(typeof value === 'object' && value) {",
                                Template.indent([
                                        "if((mode & 4) && value.__esModule) return value;",
                                        "if((mode & 16) && typeof value.then === 'function') return value;"
                                ]),
                                "}",
                                "var ns = Object.create(null);",
                                `${RuntimeGlobals.makeNamespaceObject}(ns);`,
                                "var def = {};",
                                "leafPrototypes = leafPrototypes || [null, getProto({}), getProto([]), getProto(getProto)];",
                                "for(var current = mode & 2 && value; (typeof current == 'object' || typeof current == 'function') && !~leafPrototypes.indexOf(current); current = getProto(current)) {",
                                Template.indent([
                                        `Object.getOwnPropertyNames(current).forEach(${runtimeTemplate.expressionFunction(
                                                `def[key] = ${runtimeTemplate.returningFunction("value[key]", "")}`,
                                                "key"
                                        )});`
                                ]),
                                "}",
                                `def['default'] = ${runtimeTemplate.returningFunction("value", "")};`,
                                `${RuntimeGlobals.definePropertyGetters}(ns, def);`,
                                "return ns;"
                        ]),
                        "};"
                ]);
        }
}

module.exports = CreateFakeNamespaceObjectRuntimeModule;