Replace the existing unittest APIs with the new runner infrastructure.

lib/src/test_case.dart

 // Copyright (c) 2013, 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.
 
 library unittest.test_case;
 
-import '../unittest.dart';
-
-/// An individual unit test.
+/// This is a stub class used to preserve compatibility with unittest 0.11.*.
+///
+/// It will be removed before the next version is released.
+@deprecated
 abstract class TestCase {
-  /// A unique numeric identifier for this test case.
   int get id;
-
-  /// A description of what the test is specifying.
   String get description;
-
-  /// The error or failure message for the tests.
-  ///
-  /// Initially an empty string.
   String get message;
-
-  /// The result of the test case.
-  ///
-  /// If the test case has is completed, this will be one of [PASS], [FAIL], or
-  /// [ERROR]. Otherwise, it will be `null`.
   String get result;
-
-  /// Returns whether this test case passed.
   bool get passed;
-
-  /// The stack trace for the error that caused this test case to fail, or
-  /// `null` if it succeeded.
   StackTrace get stackTrace;
-
-  /// The name of the group within which this test is running.
   String get currentGroup;
-
-  /// The time the test case started running.
-  ///
-  /// `null` if the test hasn't yet begun running.
   DateTime get startTime;
-
-  /// The amount of time the test case took.
-  ///
-  /// `null` if the test hasn't finished running.
   Duration get runningTime;
-
-  /// Whether this test is enabled.
-  ///
-  /// Disabled tests won't be run.
   bool get enabled;
-
-  /// Whether this test case has finished running.
-  bool get isComplete => !enabled || result != null;
+  final isComplete = false;
 }