Fixes in codegen and test script

lib/src/utils.dart

 // Copyright (c) 2015, 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.
 
 /// Holds a couple utility functions used at various places in the system.
 library dev_compiler.src.utils;
 
 import 'dart:io';
 
 import 'package:path/path.dart' as path;
@@ skipping 19 matching lines @@
   if (uri.scheme != "dart") return false;
   return Identifier.isPrivateName(uri.path);
 }
 
 /// Choose a canonical name from the library element. This is safe to use as a
 /// namespace in JS and Dart code generation.  This never uses the library's
 /// name (the identifier in the `library` declaration) as it doesn't have any
 /// meaningful rules enforced.
 String canonicalLibraryName(LibraryElement library) {
   var uri = library.source.uri;
-  return path.basenameWithoutExtension(uri.pathSegments.last);
+  var name = path.basenameWithoutExtension(uri.pathSegments.last);
+  return _toIdentifier(name);
+}
+
+/// Sanitize [name] to make it into a valid identifier.
+String _toIdentifier(String name) {
+  if (name.length == 0) return r'$';
+  name = name.replaceAllMapped(new RegExp(r'[^A-Za-z_$0-9]'), (c) => '_');

[Jennifer Messerly, 2015/03/11 20:28:54]

are we worried about collisions? would an escaping scheme be better? or fall
back to library's name?

[Siggi Cherem (dart-lang), 2015/03/11 23:27:22]

Good point - went with an escaping scheme.

+  if (name.startsWith(new RegExp('[0-9]'))) return '\$$name';
+  return name;

[Jennifer Messerly, 2015/03/11 20:28:54]

do we need to exclude JS keywords if generating JS? (e.g. `switch.js`)

[Siggi Cherem (dart-lang), 2015/03/11 23:27:22]

Good point - I made isJsKeyword in js_ast public for this purpose and moved to a
separate library. Not sure if we are trying to minimize changes there though.

[Jennifer Messerly, 2015/03/11 23:48:00]

Generally I've been sticking to adds. But that was a method I added, so no
worries about moving it :)

 }
 
 /// Returns all libraries transitively imported or exported from [start].
 Iterable<LibraryElement> reachableLibraries(LibraryElement start) {
   var results = <LibraryElement>[];
   var seen = new Set();
   void find(LibraryElement lib) {
     if (seen.contains(lib)) return;
     seen.add(lib);
     results.add(lib);
@@ skipping 209 matching lines @@
       locationForOffset(unit, uri, end), '$text');
 }
 
 /// Computes a hash for the given contents.
 String computeHash(String contents) {
   if (contents == null || contents == '') return null;
   return CryptoUtils.bytesToHex((new MD5()..add(contents.codeUnits)).close());
 }
 
 String resourceOutputPath(Uri resourceUri) => resourceUri.path;