source: imaps-frontend/node_modules/webpack/lib/wasm-async/AsyncWebAssemblyJavascriptGenerator.js

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

"use strict";

const { RawSource } = require("webpack-sources");
const Generator = require("../Generator");
const InitFragment = require("../InitFragment");
const { WEBASSEMBLY_TYPES } = require("../ModuleSourceTypesConstants");
const RuntimeGlobals = require("../RuntimeGlobals");
const Template = require("../Template");
const WebAssemblyImportDependency = require("../dependencies/WebAssemblyImportDependency");

/** @typedef {import("webpack-sources").Source} Source */
/** @typedef {import("../../declarations/WebpackOptions").OutputNormalized} OutputOptions */
/** @typedef {import("../DependencyTemplates")} DependencyTemplates */
/** @typedef {import("../Generator").GenerateContext} GenerateContext */
/** @typedef {import("../Module")} Module */
/** @typedef {import("../Module").SourceTypes} SourceTypes */
/** @typedef {import("../NormalModule")} NormalModule */
/** @typedef {import("../RuntimeTemplate")} RuntimeTemplate */

/**
 * @typedef {{ request: string, importVar: string }} ImportObjRequestItem
 */

class AsyncWebAssemblyJavascriptGenerator extends Generator {
        /**
         * @param {OutputOptions["webassemblyModuleFilename"]} filenameTemplate template for the WebAssembly module filename
         */
        constructor(filenameTemplate) {
                super();
                this.filenameTemplate = filenameTemplate;
        }

        /**
         * @param {NormalModule} module fresh module
         * @returns {SourceTypes} available types (do not mutate)
         */
        getTypes(module) {
                return WEBASSEMBLY_TYPES;
        }

        /**
         * @param {NormalModule} module the module
         * @param {string=} type source type
         * @returns {number} estimate size of the module
         */
        getSize(module, type) {
                return 40 + module.dependencies.length * 10;
        }

        /**
         * @param {NormalModule} module module for which the code should be generated
         * @param {GenerateContext} generateContext context for generate
         * @returns {Source | null} generated code
         */
        generate(module, generateContext) {
                const {
                        runtimeTemplate,
                        chunkGraph,
                        moduleGraph,
                        runtimeRequirements,
                        runtime
                } = generateContext;
                runtimeRequirements.add(RuntimeGlobals.module);
                runtimeRequirements.add(RuntimeGlobals.moduleId);
                runtimeRequirements.add(RuntimeGlobals.exports);
                runtimeRequirements.add(RuntimeGlobals.instantiateWasm);
                /** @type {InitFragment<InitFragment<string>>[]} */
                const initFragments = [];
                /** @type {Map<Module, ImportObjRequestItem>} */
                const depModules = new Map();
                /** @type {Map<string, WebAssemblyImportDependency[]>} */
                const wasmDepsByRequest = new Map();
                for (const dep of module.dependencies) {
                        if (dep instanceof WebAssemblyImportDependency) {
                                const module = /** @type {Module} */ (moduleGraph.getModule(dep));
                                if (!depModules.has(module)) {
                                        depModules.set(module, {
                                                request: dep.request,
                                                importVar: `WEBPACK_IMPORTED_MODULE_${depModules.size}`
                                        });
                                }
                                let list = wasmDepsByRequest.get(dep.request);
                                if (list === undefined) {
                                        list = [];
                                        wasmDepsByRequest.set(dep.request, list);
                                }
                                list.push(dep);
                        }
                }

                /** @type {Array<string>} */
                const promises = [];

                const importStatements = Array.from(
                        depModules,
                        ([importedModule, { request, importVar }]) => {
                                if (moduleGraph.isAsync(importedModule)) {
                                        promises.push(importVar);
                                }
                                return runtimeTemplate.importStatement({
                                        update: false,
                                        module: importedModule,
                                        chunkGraph,
                                        request,
                                        originModule: module,
                                        importVar,
                                        runtimeRequirements
                                });
                        }
                );
                const importsCode = importStatements.map(([x]) => x).join("");
                const importsCompatCode = importStatements.map(([_, x]) => x).join("");

                const importObjRequestItems = Array.from(
                        wasmDepsByRequest,
                        ([request, deps]) => {
                                const exportItems = deps.map(dep => {
                                        const importedModule =
                                                /** @type {Module} */
                                                (moduleGraph.getModule(dep));
                                        const importVar =
                                                /** @type {ImportObjRequestItem} */
                                                (depModules.get(importedModule)).importVar;
                                        return `${JSON.stringify(
                                                dep.name
                                        )}: ${runtimeTemplate.exportFromImport({
                                                moduleGraph,
                                                module: importedModule,
                                                request,
                                                exportName: dep.name,
                                                originModule: module,
                                                asiSafe: true,
                                                isCall: false,
                                                callContext: false,
                                                defaultInterop: true,
                                                importVar,
                                                initFragments,
                                                runtime,
                                                runtimeRequirements
                                        })}`;
                                });
                                return Template.asString([
                                        `${JSON.stringify(request)}: {`,
                                        Template.indent(exportItems.join(",\n")),
                                        "}"
                                ]);
                        }
                );

                const importsObj =
                        importObjRequestItems.length > 0
                                ? Template.asString([
                                                "{",
                                                Template.indent(importObjRequestItems.join(",\n")),
                                                "}"
                                        ])
                                : undefined;

                const instantiateCall = `${RuntimeGlobals.instantiateWasm}(${module.exportsArgument}, ${
                        module.moduleArgument
                }.id, ${JSON.stringify(
                        chunkGraph.getRenderedModuleHash(module, runtime)
                )}${importsObj ? `, ${importsObj})` : ")"}`;

                if (promises.length > 0)
                        runtimeRequirements.add(RuntimeGlobals.asyncModule);

                const source = new RawSource(
                        promises.length > 0
                                ? Template.asString([
                                                `var __webpack_instantiate__ = ${runtimeTemplate.basicFunction(
                                                        `[${promises.join(", ")}]`,
                                                        `${importsCompatCode}return ${instantiateCall};`
                                                )}`,
                                                `${RuntimeGlobals.asyncModule}(${
                                                        module.moduleArgument
                                                }, async ${runtimeTemplate.basicFunction(
                                                        "__webpack_handle_async_dependencies__, __webpack_async_result__",
                                                        [
                                                                "try {",
                                                                importsCode,
                                                                `var __webpack_async_dependencies__ = __webpack_handle_async_dependencies__([${promises.join(
                                                                        ", "
                                                                )}]);`,
                                                                `var [${promises.join(
                                                                        ", "
                                                                )}] = __webpack_async_dependencies__.then ? (await __webpack_async_dependencies__)() : __webpack_async_dependencies__;`,
                                                                `${importsCompatCode}await ${instantiateCall};`,
                                                                "__webpack_async_result__();",
                                                                "} catch(e) { __webpack_async_result__(e); }"
                                                        ]
                                                )}, 1);`
                                        ])
                                : `${importsCode}${importsCompatCode}module.exports = ${instantiateCall};`
                );

                return InitFragment.addToSource(source, initFragments, generateContext);
        }
}

module.exports = AsyncWebAssemblyJavascriptGenerator;