Function detectModuleFormat

lib/internal/modules/esm/get_format.js:87–92

* Determine whether the given ambiguous source contains CommonJS or ES module syntax. * @param {string | Buffer | undefined} [source] * @param {URL} url * @returns {'module'|'commonjs'}

(source, url)

 * @returns {'module'|'commonjs'}
 */
function detectModuleFormat(source, url) {
  const detectModule = getOptionValue('--experimental-detect-module');
  if (!source) { return detectModule ? null : 'commonjs'; }
  if (!detectModule) { return 'commonjs'; }
  return containsModuleSyntax(`${source}`, fileURLToPath(url), url) ? 'module' : 'commonjs';
}

/**
 * @param {URL} parsed