Added test setup/teardown.

lib/unittest/test_case.dart

 // Copyright (c) 2011, 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.
 
 /**
  * testcase.dart: this file is sourced by unittest.dart. It defines [TestCase]
  * and assumes unittest defines the type [TestFunction].
  */
 
-
 /** Summarizes information about a single test case. */
 class TestCase {
   /** Identifier for this test. */
   final int id;
 
   /** A description of what the test is specifying. */
   final String description;
 
+  /** The setup function to call before the test, if any. */
+  final _setup;
+
+  /** The teardown function to call after the test, if any. */
+  final _teardown;
+
   /** The body of the test case. */
   final TestFunction test;
 
   /** Total number of callbacks to wait for before the test completes. */
   int callbacks;
 
   /** Error or failure message. */
   String message = '';
 
   /**
    * One of [_PASS], [_FAIL], or [_ERROR] or [null] if the test hasn't run yet.
    */
   String result;
 
   /** Stack trace associated with this test, or null if it succeeded. */
   String stackTrace;
 
   /** The group (or groups) under which this test is running. */
   final String currentGroup;
- 
+
   Date startTime;
 
   Duration runningTime;
 
   TestCase(this.id, this.description, this.test, this.callbacks)
-  : currentGroup = _currentGroup;
+  : currentGroup = _currentGroup,
+    _setup = _testSetup,
+    _teardown = _testTeardown;
 
   bool get isComplete() => result != null;
 
+  void run() {
+    if (_setup != null) {
+      _setup();
+    }
+    try {
+      test();
+    } finally {
+      if (_teardown != null) {
+        _teardown();
+      }
+    }
+  }
+
   void pass() {
     result = _PASS;
   }
 
   void fail(String message, String stackTrace) {
     result = _FAIL;
     this.message = message;
     this.stackTrace = stackTrace;
   }
 
   void error(String message, String stackTrace) {
     result = _ERROR;
     this.message = message;
     this.stackTrace = stackTrace;
   }
 }