Function createCJSModuleWrap

lib/internal/modules/esm/translators.js:204–276

* Creates a ModuleWrap object for a CommonJS module. * @param {string} url - The URL of the module. * @param {import('./loader').TranslateContext} translateContext Context for the translator * @param {string|undefined} parentURL URL of the module initiating the module loading for the first time.

(url, translateContext, parentURL)

 * @returns {ModuleWrap} The ModuleWrap object for the CommonJS module.
 */
function createCJSModuleWrap(url, translateContext, parentURL) {
  debug(`Translating CJSModule ${url}`, translateContext);

  const { format: sourceFormat } = translateContext;
  let { source } = translateContext;
  const isMain = (parentURL === undefined);
  const filename = urlToFilename(url);
  try {
    // In case the source was not provided by the `load` step, we need fetch it now.
    source = stringify(source ?? getSourceSync(new URL(url)).source);
  } catch {
    // Continue regardless of error.
  }

  const { exportNames, module } = cjsPreparseModuleExports(filename, source, sourceFormat);
  cjsCache.set(url, module);

  const wrapperNames = [...exportNames];
  if (!exportNames.has('default')) {
    ArrayPrototypePush(wrapperNames, 'default');
  }
  if (!exportNames.has('module.exports')) {
    ArrayPrototypePush(wrapperNames, 'module.exports');
  }

  if (isMain) {
    setOwnProperty(process, 'mainModule', module);
  }

  return new ModuleWrap(url, undefined, wrapperNames, function() {
    debug(`Loading CJSModule ${url}`);

    if (!module.loaded) {
      // For backward-compatibility, it's possible for async hooks to return a nullish value for
      // CJS source associated with a `file:` URL - that usually means the source is not
      // customized (is loaded by default load) or the hook author wants it to be reloaded
      // through CJS routine. In this case, the source is obtained by calling the
      // Module._load().
      if (translateContext.translatorKey === 'commonjs-sync' ||
          translateContext.isSourceLoadedSynchronously ||
          translateContext.source == null) {
        loadCJSModuleWithModuleLoad(module, source, url, filename, !!isMain, translateContext);
      } else {  // CommonJS with source customized by async hooks
        // This may be eventually removed when module.register() reaches end-of-life.
        loadCJSModuleWithSpecialRequire(module, source, url, filename, !!isMain, translateContext);
      }
    }

    let exports;
    if (module[kModuleExport] !== undefined) {
      exports = module[kModuleExport];
      module[kModuleExport] = undefined;
    } else {
      ({ exports } = module);
    }
    for (const exportName of exportNames) {
      if (exportName === 'default' || exportName === 'module.exports' ||
          !ObjectPrototypeHasOwnProperty(exports, exportName)) {