async function _tryRequire()

in src/UserFunction.js [138:194]

• 39 lines of code
• 8 McCabe index (conditional complexity)

async function _tryRequire(appRoot, moduleRoot, module) {
  verbose(
    'Try loading as commonjs: ',
    module,
    ' with paths: ,',
    appRoot,
    moduleRoot,
  );

  const lambdaStylePath = path.resolve(appRoot, moduleRoot, module);

  // Extensionless files are loaded via require.
  const extensionless = _tryRequireFile(lambdaStylePath);
  if (extensionless) {
    return extensionless;
  }

  // If package.json type != module, .js files are loaded via require.
  const pjHasModule = _hasPackageJsonTypeModule(lambdaStylePath);
  if (!pjHasModule) {
    const loaded = _tryRequireFile(lambdaStylePath, '.js');
    if (loaded) {
      return loaded;
    }
  }

  // If still not loaded, try .js, .mjs, and .cjs in that order.
  // Files ending with .js are loaded as ES modules when the nearest parent package.json
  // file contains a top-level field "type" with a value of "module".
  // https://nodejs.org/api/packages.html#packages_type
  const loaded =
    (pjHasModule && (await _tryAwaitImport(lambdaStylePath, '.js'))) ||
    (await _tryAwaitImport(lambdaStylePath, '.mjs')) ||
    _tryRequireFile(lambdaStylePath, '.cjs');
  if (loaded) {
    return loaded;
  }

  verbose(
    'Try loading as commonjs: ',
    module,
    ' with path(s): ',
    appRoot,
    moduleRoot,
  );

  // Why not just require(module)?
  // Because require() is relative to __dirname, not process.cwd(). And the
  // runtime implementation is not located in /var/task
  // This won't work (yet) for esModules as import.meta.resolve is still experimental
  // See: https://nodejs.org/api/esm.html#esm_import_meta_resolve_specifier_parent
  const nodeStylePath = require.resolve(module, {
    paths: [appRoot, moduleRoot],
  });

  return require(nodeStylePath);
}