Add suite information to the JSON reporter.

lib/src/runner.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.
 
 import 'dart:async';
 import 'dart:io';
 
 import 'package:async/async.dart';
 
 import 'backend/group.dart';
@@ skipping 163 matching lines @@
   /// Return a stream of [LoadSuite]s in [_config.paths].
   ///
   /// Only tests that match [_config.pattern] will be included in the
   /// suites once they're loaded.
   Stream<LoadSuite> _loadSuites() {
     return mergeStreams(_config.paths.map((path) {
       if (new Directory(path).existsSync()) return _loader.loadDir(path);
       if (new File(path).existsSync()) return _loader.loadFile(path);
 
       return new Stream.fromIterable([
-        new LoadSuite("loading $path", () =>
-            throw new LoadException(path, 'Does not exist.'))
+        new LoadSuite.forLoadException(
+            new LoadException(path, 'Does not exist.'))
       ]);
     })).map((loadSuite) {
       return loadSuite.changeSuite((suite) {
         _warnForUnknownTags(suite);
 
         return suite.filter((test) {
           // Skip any tests that don't match the given pattern.
           if (_config.pattern != null && !test.name.contains(_config.pattern)) {
             return false;
           }
@@ skipping 103 matching lines @@
       await _debugOperation.valueOrCancellation();
     }).listen(null);
 
     var results = await Future.wait([
       _suiteSubscription.asFuture().then((_) => _engine.suiteSink.close()),
       _engine.run()
     ]);
     return results.last;
   }
 }