Don't run tests against pinned barback versions in third_party.

tools/testing/dart/test_suite.dart

 // Copyright (c) 2012, 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.
 
 /**
  * Classes and methods for enumerating and preparing tests.
  *
  * This library includes:
  *
  * - Creating tests by listing all the Dart files in certain directories,
@@ skipping 397 matching lines @@
     var futures = [
       listDir(dartDir.append('pkg'), isValid),
       listDir(dartDir.append('pkg').append('third_party'), isValid),
       listDir(dartDir.append('third_party').append('pkg'), isValid),
     ];
     return Future.wait(futures).then((results) {
       var packageDirectories = {};
       for (var result in results) {
         for (var packageTuple in result) {
           String packageName = packageTuple[0];
+
+          // Some packages are pinned to specific versions. We can ignore those
+          // for the purposes of testing.
+          if (packageName.contains('-')) continue;

[kustermann, 2014/05/27 23:28:17]

I'd prefer if you move this logic into the "isValid(packageName)" function above
and constrain it more, something like:

isValid(packageName) {
  return !['third_party', 'barback-0.13.0'].contains(packageName);
}

You're more familiar with the package name constraints: Is "-" disallowed in the
directory names for pub packages? If so, I'm also fine with "-", but I'd still
move it up to "isValid(...)" and extend the comment saying that directories
containing "-" are not valid pub packages.

[nweiz, 2014/05/27 23:56:22]

Done.
Package names can't contain "-"; they have to be valid Dart identifiers. I think
it's better to check for "-" because we're likely to add more pinned versions of
barback in the future.

+
           String fullPath = packageTuple[1];
           String yamlFile =
               new Path(fullPath).append('pubspec.yaml').toNativePath();
           if (new File(yamlFile).existsSync()) {
             packageDirectories[packageName] = fullPath;
           }
         }
       }
       return packageDirectories;
     });
@@ skipping 1791 matching lines @@
  * $pass tests are expected to pass
  * $failOk tests are expected to fail that we won't fix
  * $fail tests are expected to fail that we should fix
  * $crash tests are expected to crash that we should fix
  * $timeout tests are allowed to timeout
  * $compileErrorSkip tests are skipped on browsers due to compile-time error
 """;
     print(report);
   }
 }