child_process: handling fork( path, undefined / null, obj )

Closes: #20749

Author: shobhitchittora

lib/child_process.js

@@ -69,6 +69,11 @@ exports.fork = function fork(modulePath /* , args, options */) {
     args = arguments[pos++];
   }
 
+  if (pos < arguments.length && (arguments[pos] === undefined ||
+    arguments[pos] === null)) {
+    pos++;
+  }
+
   if (pos < arguments.length && arguments[pos] != null) {
     if (typeof arguments[pos] !== 'object') {
       throw new ERR_INVALID_ARG_VALUE(`arguments[${pos}]`, arguments[pos]);