Better runtime type checks.

frog/frog.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #import('lib/node/node.dart');
 #import('file_system_node.dart');
 #import('lang.dart');
 
 void main() {
   // Get the home directory from our executable.
   var homedir = path.dirname(fs.realpathSync(process.argv[1]));
-  if (compile(homedir, process.argv, new NodeFileSystem())) {
+
+  // Note: we create a copy of argv here because the one that is passed in is
+  // potentially a JS Array object from outside the sandbox. Hence it will have
+  // the wrong prototype.
+  var argv = new List.from(process.argv);

[jimhug, 2011/11/07 16:41:26]

TODO: This seems like a bug in the node interop that this would be needed here. 
I think any such shenanigans should be nicely encapsulated in whatever wrappers
we use to expose node.

[Jennifer Messerly, 2011/11/07 22:13:10]

It's a bug in our createSandbox. We pass certain objects (require, process,
console) to the child. These objects (by design of Node's sandbox) don't share
prototype with the parent. That part is good. The bad is that we are forcing the
child code to deal with the problem. The only fix I can think of is injecting
some code into the generate JS that patches the prototypes of those 3 objects,
as well as process.argv.

+
+  if (compile(homedir, argv, new NodeFileSystem())) {
     var code = world.getGeneratedCode();
     if (!options.compileOnly) {
-      process.argv = [process.argv[0], process.argv[1]];
+      process.argv = [argv[0], argv[1]];
       process.argv.addAll(options.childArgs);
       vm.runInNewContext(code, createSandbox());
     }
   } else {
     process.exit(1);
   }
 }