child_process: check execFile and fork args

Port of joyent/node commits:

 * nodejs/node-v0.x-archive@e17c5a7
 * nodejs/node-v0.x-archive@70dafa7

Pull over test-child-process-spawn-typeerror.js from v0.12, replacing
the existing test in master. The new test includes a broader set of
tests on the various arg choices and throws.

Author: jasnell

lib/child_process.js

@@ -23,6 +23,8 @@ exports.fork = function(modulePath /*, args, options*/) {
   if (Array.isArray(arguments[1])) {
     args = arguments[1];
     options = util._extend({}, arguments[2]);
+  } else if (arguments[1] && typeof arguments[1] !== 'object') {
+    throw new TypeError('Incorrect value of args option');
   } else {
     args = [];
     options = util._extend({}, arguments[1]);
@@ -104,7 +106,7 @@ exports.exec = function(command /*, options, callback*/) {
 
 
 exports.execFile = function(file /*, args, options, callback*/) {
-  var args, callback;
+  var args = [], callback;
   var options = {
     encoding: 'utf8',
     timeout: 0,
@@ -114,18 +116,26 @@ exports.execFile = function(file /*, args, options, callback*/) {
     env: null
   };
 
-  // Parse the parameters.
+  // Parse the optional positional parameters.
+  var pos = 1;
+  if (pos < arguments.length && Array.isArray(arguments[pos])) {
+    args = arguments[pos++];
+  } else if (pos < arguments.length && arguments[pos] == null) {
+    pos++;
+  }
 
-  if (typeof arguments[arguments.length - 1] === 'function') {
-    callback = arguments[arguments.length - 1];
+  if (pos < arguments.length && typeof arguments[pos] === 'object') {
+    options = util._extend(options, arguments[pos++]);
+  } else if (pos < arguments.length && arguments[pos] == null) {
+    pos++;
   }
 
-  if (Array.isArray(arguments[1])) {
-    args = arguments[1];
-    options = util._extend(options, arguments[2]);
-  } else {
-    args = [];
-    options = util._extend(options, arguments[1]);
+  if (pos < arguments.length && typeof arguments[pos] === 'function') {
+    callback = arguments[pos++];
+  }
+
+  if (pos === 1 && arguments.length > 1) {
+    throw new TypeError('Incorrect value of args option');
   }
 
   var child = spawn(file, args, {

test/parallel/test-child-process-spawn-typeerror.js

@@ -1,15 +1,28 @@
 'use strict';
-var assert = require('assert');
-var child_process = require('child_process');
-var spawn = child_process.spawn;
-var cmd = require('../common').isWindows ? 'rundll32' : 'ls';
-var invalidArgsMsg = /Incorrect value of args option/;
-var invalidOptionsMsg = /options argument must be an object/;
-
-// verify that args argument must be an array
-assert.throws(function() {
-  spawn(cmd, 'this is not an array');
-}, TypeError);
+var assert = require('assert'),
+  child_process = require('child_process'),
+  spawn = child_process.spawn,
+  fork = child_process.fork,
+  execFile = child_process.execFile,
+  windows = (process.platform === 'win32'),
+  cmd = (windows) ? 'rundll32' : 'ls',
+  invalidcmd = 'hopefully_you_dont_have_this_on_your_machine',
+  invalidArgsMsg = /Incorrect value of args option/,
+  invalidOptionsMsg = /options argument must be an object/,
+  empty = require('../common').fixturesDir + '/empty.js',
+  errors = 0;
+
+try {
+  // Ensure this throws a TypeError
+  var child = spawn(invalidcmd, 'this is not an array');
+
+  child.on('error', function(err) {
+    errors++;
+  });
+
+} catch (e) {
+  assert.equal(e instanceof TypeError, true);
+}
 
 // verify that valid argument combinations do not throw
 assert.doesNotThrow(function() {
@@ -49,3 +62,87 @@ assert.throws(function() {
   spawn(cmd, [], 1);
 }, invalidOptionsMsg);
 
+process.on('exit', function() {
+  assert.equal(errors, 0);
+});
+
+// Argument types for combinatorics
+var a = [],
+    o = {},
+    c = (function callback() {}),
+    s = 'string',
+    u = undefined,
+    n = null;
+
+// function spawn(file=f [,args=a] [, options=o]) has valid combinations:
+//   (f)
+//   (f, a)
+//   (f, a, o)
+//   (f, o)
+assert.doesNotThrow(function() { spawn(cmd); });
+assert.doesNotThrow(function() { spawn(cmd, a); });
+assert.doesNotThrow(function() { spawn(cmd, a, o); });
+assert.doesNotThrow(function() { spawn(cmd, o); });
+
+// Variants of undefined as explicit 'no argument' at a position
+assert.doesNotThrow(function() { spawn(cmd, u, o); });
+assert.doesNotThrow(function() { spawn(cmd, a, u); });
+
+assert.throws(function() { spawn(cmd, n, o); }, TypeError);
+assert.throws(function() { spawn(cmd, a, n); }, TypeError);
+
+assert.throws(function() { spawn(cmd, s); }, TypeError);
+assert.throws(function() { spawn(cmd, a, s); }, TypeError);
+
+
+// verify that execFile has same argument parsing behaviour as spawn
+//
+// function execFile(file=f [,args=a] [, options=o] [, callback=c]) has valid
+// combinations:
+//   (f)
+//   (f, a)
+//   (f, a, o)
+//   (f, a, o, c)
+//   (f, a, c)
+//   (f, o)
+//   (f, o, c)
+//   (f, c)
+assert.doesNotThrow(function() { execFile(cmd); });
+assert.doesNotThrow(function() { execFile(cmd, a); });
+assert.doesNotThrow(function() { execFile(cmd, a, o); });
+assert.doesNotThrow(function() { execFile(cmd, a, o, c); });
+assert.doesNotThrow(function() { execFile(cmd, a, c); });
+assert.doesNotThrow(function() { execFile(cmd, o); });
+assert.doesNotThrow(function() { execFile(cmd, o, c); });
+assert.doesNotThrow(function() { execFile(cmd, c); });
+
+// Variants of undefined as explicit 'no argument' at a position
+assert.doesNotThrow(function() { execFile(cmd, u, o, c); });
+assert.doesNotThrow(function() { execFile(cmd, a, u, c); });
+assert.doesNotThrow(function() { execFile(cmd, a, o, u); });
+assert.doesNotThrow(function() { execFile(cmd, n, o, c); });
+assert.doesNotThrow(function() { execFile(cmd, a, n, c); });
+assert.doesNotThrow(function() { execFile(cmd, a, o, n); });
+
+// string is invalid in arg position (this may seem strange, but is
+// consistent across node API, cf. `net.createServer('not options', 'not
+// callback')`
+assert.throws(function() { execFile(cmd, s, o, c); }, TypeError);
+assert.doesNotThrow(function() { execFile(cmd, a, s, c); });
+assert.doesNotThrow(function() { execFile(cmd, a, o, s); });
+
+
+// verify that fork has same argument parsing behaviour as spawn
+//
+// function fork(file=f [,args=a] [, options=o]) has valid combinations:
+//   (f)
+//   (f, a)
+//   (f, a, o)
+//   (f, o)
+assert.doesNotThrow(function() { fork(empty); });
+assert.doesNotThrow(function() { fork(empty, a); });
+assert.doesNotThrow(function() { fork(empty, a, o); });
+assert.doesNotThrow(function() { fork(empty, o); });
+
+assert.throws(function() { fork(empty, s); }, TypeError);
+assert.doesNotThrow(function() { fork(empty, a, s); }, TypeError);