Handle "fail_" style tests in reflective tests.

pkg/analyzer/test/reflective_tests.dart

 // Copyright (c) 2014, 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 reflective_tests;
 
 import 'dart:async';
 import 'dart:mirrors';
 
 import 'package:unittest/unittest.dart';
@@ skipping 31 matching lines @@
           return _runTest(classMirror, symbol);
         });
         return;
       }
       // solo_test_
       if (memberName.startsWith('solo_test_')) {
         solo_test(memberName, () {
           return _runTest(classMirror, symbol);
         });
       }
+      // fail_test_
+      if (memberName.startsWith('fail_')) {
+        test(memberName, () {
+          return _runFailingTest(classMirror, symbol);
+        });
+      }
+      // solo_fail_test_
+      if (memberName.startsWith('solo_fail_')) {
+        solo_test(memberName, () {
+          return _runFailingTest(classMirror, symbol);
+        });
+      }
     });
   });
 }
 
-
 Future _invokeSymbolIfExists(InstanceMirror instanceMirror, Symbol symbol) {
   var invocationResult = null;
   try {
     invocationResult = instanceMirror.invoke(symbol, []).reflectee;
   } on NoSuchMethodError catch (e) {
   }
   if (invocationResult is Future) {
     return invocationResult;
   } else {
     return new Future.value(invocationResult);
   }
 }
 
 
+/**
+ * Run a test that is expected to fail, and confirm that it fails.
+ *
+ * This properly handles the following cases:
+ * - The test fails by throwing an exception
+ * - The test returns a future which completes with an error.
+ *
+ * However, it does not handle the case where the test creates an asynchronous
+ * callback using expectAsync(), and that callback generates a failure.
+ */
+Future _runFailingTest(ClassMirror classMirror, Symbol symbol) {
+  return new Future(() => _runTest(classMirror, symbol)).then((_) {
+    fail('Test passed - expected to fail.');
+  }, onError: (_) {});
+}
+
+
 _runTest(ClassMirror classMirror, Symbol symbol) {
   InstanceMirror instanceMirror = classMirror.newInstance(new Symbol(''), []);
   return _invokeSymbolIfExists(
       instanceMirror,
       #setUp).then(
           (_) =>
               instanceMirror.invoke(
                   symbol,
                   [
                       ]).reflectee).whenComplete(
                           () => _invokeSymbolIfExists(instanceMirror, #tearDown));
 }
 
 
 /**
  * A marker annotation used to instruct dart2js to keep reflection information
  * for the annotated classes.
  */
 class ReflectiveTestCase {
   const ReflectiveTestCase();
 }