source: frontend/node_modules/webpack/lib/container/RemoteRuntimeModule.js

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

"use strict";

const RuntimeGlobals = require("../RuntimeGlobals");
const RuntimeModule = require("../RuntimeModule");
const Template = require("../Template");

/** @typedef {import("../Chunk")} Chunk */
/** @typedef {import("../Chunk").ChunkId} ChunkId */
/** @typedef {import("../ChunkGraph")} ChunkGraph */
/** @typedef {import("../ChunkGraph").ModuleId} ModuleId */
/** @typedef {import("../Compilation")} Compilation */
/** @typedef {import("./RemoteModule")} RemoteModule */

class RemoteRuntimeModule extends RuntimeModule {
        constructor() {
                super("remotes loading");
        }

        /**
         * Generates runtime code for this runtime module.
         * @returns {string | null} runtime code
         */
        generate() {
                const compilation = /** @type {Compilation} */ (this.compilation);
                const chunkGraph = /** @type {ChunkGraph} */ (this.chunkGraph);
                const { runtimeTemplate, moduleGraph } = compilation;
                /** @type {Record<ChunkId, ModuleId[]>} */
                const chunkToRemotesMapping = {};
                /** @type {Record<ModuleId, [string, string, ModuleId]>} */
                const idToExternalAndNameMapping = {};
                for (const chunk of /** @type {Chunk} */ (
                        this.chunk
                ).getAllReferencedChunks()) {
                        const modules = chunkGraph.getChunkModulesIterableBySourceType(
                                chunk,
                                "remote"
                        );
                        if (!modules) continue;
                        /** @type {ModuleId[]} */
                        const remotes = (chunkToRemotesMapping[
                                /** @type {ChunkId} */
                                (chunk.id)
                        ] = []);
                        for (const m of modules) {
                                const module = /** @type {RemoteModule} */ (m);
                                const name = module.internalRequest;
                                const id = /** @type {ModuleId} */ (chunkGraph.getModuleId(module));
                                const shareScope = module.shareScope;
                                const dep = module.dependencies[0];
                                const externalModule = moduleGraph.getModule(dep);
                                const externalModuleId =
                                        /** @type {ModuleId} */
                                        (externalModule && chunkGraph.getModuleId(externalModule));
                                remotes.push(id);
                                idToExternalAndNameMapping[id] = [shareScope, name, externalModuleId];
                        }
                }
                return Template.asString([
                        `var chunkMapping = ${JSON.stringify(
                                chunkToRemotesMapping,
                                null,
                                "\t"
                        )};`,
                        `var idToExternalAndNameMapping = ${JSON.stringify(
                                idToExternalAndNameMapping,
                                null,
                                "\t"
                        )};`,
                        `${
                                RuntimeGlobals.ensureChunkHandlers
                        }.remotes = ${runtimeTemplate.basicFunction("chunkId, promises", [
                                `if(${RuntimeGlobals.hasOwnProperty}(chunkMapping, chunkId)) {`,
                                Template.indent([
                                        `chunkMapping[chunkId].forEach(${runtimeTemplate.basicFunction("id", [
                                                `var getScope = ${RuntimeGlobals.currentRemoteGetScope};`,
                                                "if(!getScope) getScope = [];",
                                                "var data = idToExternalAndNameMapping[id];",
                                                "if(getScope.indexOf(data) >= 0) return;",
                                                "getScope.push(data);",
                                                "if(data.p) return promises.push(data.p);",
                                                `var onError = ${runtimeTemplate.basicFunction("error", [
                                                        'if(!error) error = new Error("Container missing");',
                                                        'if(typeof error.message === "string")',
                                                        Template.indent(
                                                                "error.message += '\\nwhile loading \"' + data[1] + '\" from ' + data[2];"
                                                        ),
                                                        `${
                                                                RuntimeGlobals.moduleFactories
                                                        }[id] = ${runtimeTemplate.basicFunction("", ["throw error;"])}`,
                                                        "data.p = 0;"
                                                ])};`,
                                                `var handleFunction = ${runtimeTemplate.basicFunction(
                                                        "fn, arg1, arg2, d, next, first",
                                                        [
                                                                "try {",
                                                                Template.indent([
                                                                        "var promise = fn(arg1, arg2);",
                                                                        "if(promise && promise.then) {",
                                                                        Template.indent([
                                                                                `var p = promise.then(${runtimeTemplate.returningFunction(
                                                                                        "next(result, d)",
                                                                                        "result"
                                                                                )}, onError);`,
                                                                                "if(first) promises.push(data.p = p); else return p;"
                                                                        ]),
                                                                        "} else {",
                                                                        Template.indent(["return next(promise, d, first);"]),
                                                                        "}"
                                                                ]),
                                                                "} catch(error) {",
                                                                Template.indent(["onError(error);"]),
                                                                "}"
                                                        ]
                                                )}`,
                                                `var onExternal = ${runtimeTemplate.returningFunction(
                                                        `external ? handleFunction(${RuntimeGlobals.initializeSharing}, data[0], 0, external, onInitialized, first) : onError()`,
                                                        "external, _, first"
                                                )};`,
                                                `var onInitialized = ${runtimeTemplate.returningFunction(
                                                        "handleFunction(external.get, data[1], getScope, 0, onFactory, first)",
                                                        "_, external, first"
                                                )};`,
                                                `var onFactory = ${runtimeTemplate.basicFunction("factory", [
                                                        "data.p = 1;",
                                                        `${
                                                                RuntimeGlobals.moduleFactories
                                                        }[id] = ${runtimeTemplate.basicFunction("module", [
                                                                "module.exports = factory();"
                                                        ])}`
                                                ])};`,
                                                `handleFunction(${RuntimeGlobals.require}, data[2], 0, 0, onExternal, 1);`
                                        ])});`
                                ]),
                                "}"
                        ])}`
                ]);
        }
}

module.exports = RemoteRuntimeModule;