Expand the JSON reporter to enable a progress bar.

lib/src/runner/reporter/json.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:convert';
 
 import '../../backend/group.dart';
 import '../../backend/live_test.dart';
 import '../../backend/metadata.dart';
@@ skipping 48 matching lines @@
   }
 
   JsonReporter._(this._engine, {bool verboseTrace: false})
       : _verboseTrace = verboseTrace {
     _subscriptions.add(_engine.onTestStarted.listen(_onTestStarted));
 
     /// Convert the future to a stream so that the subscription can be paused or
     /// canceled.
     _subscriptions.add(_engine.success.asStream().listen(_onDone));
 
+    _subscriptions.add(_engine.onSuiteAdded.listen(null, onDone: () {
+      _emit("allSuites", {
+        "count": _engine.addedSuites.length
+      });
+    }));
+
     _emit("start", {
       "protocolVersion": "0.1.0",
       "runnerVersion": testVersion
     });
   }
 
   void pause() {
     if (_paused) return;
     _paused = true;
 
@@ skipping 108 matching lines @@
 
       var id = _nextID++;
       _groupIDs[group] = id;
 
       _emit("group", {
         "group": {
           "id": id,
           "suiteID": suiteID,
           "parentID": parentID,
           "name": group.name,
-          "metadata": _serializeMetadata(group.metadata)
+          "metadata": _serializeMetadata(group.metadata),
+          "testCount": group.testCount
         }
       });
       parentID = id;
       return id;
     }).toList();
   }
 
   /// Serializes [metadata] into a JSON-protocol-compatible map.
   Map _serializeMetadata(Metadata metadata) =>
       {"skip": metadata.skip, "skipReason": metadata.skipReason};
@@ skipping 28 matching lines @@
     _emit("done", {"success": success});
   }
 
   /// Emits an event with the given type and attributes.
   void _emit(String type, Map attributes) {
     attributes["type"] = type;
     attributes["time"] = _stopwatch.elapsed.inMilliseconds;
     print(JSON.encode(attributes));
   }
 }