Function fork

lib/child_process.js:125–175

* Spawns a new Node.js process + fork. * @param {string|URL} modulePath * @param {string[]} [args] * @param {{ * cwd?: string | URL; * detached?: boolean; * env?: Record ; * execPath?: string; * execArgv?: string[]; * gid?: number; * serialization?: string; *

(modulePath, args = [], options)

 * @returns {ChildProcess}
 */
function fork(modulePath, args = [], options) {
  modulePath = getValidatedPath(modulePath, 'modulePath');

  // Get options and args arguments.
  let execArgv;

  if (args == null) {
    args = [];
  } else if (typeof args === 'object' && !ArrayIsArray(args)) {
    options = args;
    args = [];
  } else {
    validateArray(args, 'args');
  }

  if (options != null) {
    validateObject(options, 'options');
  }
  options = { __proto__: null, ...options, shell: false };
  options.execPath ||= process.execPath;
  validateArgumentNullCheck(options.execPath, 'options.execPath');

  // Prepare arguments for fork:
  execArgv = options.execArgv || process.execArgv;
  validateArgumentsNullCheck(execArgv, 'options.execArgv');

  if (execArgv === process.execArgv && process._eval != null) {
    const index = ArrayPrototypeLastIndexOf(execArgv, process._eval);
    if (index > 0) {
      // Remove the -e switch to avoid fork bombing ourselves.
      execArgv = ArrayPrototypeSlice(execArgv);
      ArrayPrototypeSplice(execArgv, index - 1, 2);
    }
  }

  args = [...execArgv, modulePath, ...args];

  if (typeof options.stdio === 'string') {
    options.stdio = stdioStringToArray(options.stdio, 'ipc');
  } else if (!ArrayIsArray(options.stdio)) {
    // Use a separate fd=3 for the IPC channel. Inherit stdin, stdout,
    // and stderr from the parent if silent isn't set.
    options.stdio = stdioStringToArray(
      options.silent ? 'pipe' : 'inherit',
      'ipc');
  } else if (!ArrayPrototypeIncludes(options.stdio, 'ipc')) {
    throw new ERR_CHILD_PROCESS_IPC_REQUIRED('options.stdio');
  }

  return spawn(options.execPath, args, options);
}

function _forkChild(fd, serializationMode) {
  // set process.send()