Get rid of "==" in Expectation.

client/testing/unittest/unittestsuite.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.
 
 /** Base class for unit test suites run in a browser. */
 class UnitTestSuite {
 
   /** Tests executed in this suite. */
   List<TestCase> _tests;
 
@@ skipping 281 matching lines @@
     }
 
     window.dynamic/*TODO(5389254)*/.postMessage('unittest-suite-done', '*');
   }
 }
 
 /**
  * Wraps an value and provides an "==" operator that can be used to verify that
  * the value matches a given expectation.
  */
-// TODO(rnystrom): Note that because Dart does not currently allow overloading
-// != that this *cannot* be used with !=. If you do expect(1) != 2, it will do
-// the exact wrong thing. (It will invoke == which validates that 1 *does*
-// equal 2.) If we get an overloadable != operator, that can be fixed.
 class Expectation {
   final _value;
 
   Expectation(this._value);
 
   /** Asserts that the value is equivalent to the given expected value. */
-  operator ==(expected) {
+  bool equals(expected) {
     Expect.equals(expected, _value);
     return _value == expected;
   }
 
+  /** Asserts that the value is null. */
+  void isNull() {
+    Expect.equals(null, _value);
+  }
+
   /** Asserts that the value is not null. */
   void isNotNull() {
     Expect.notEquals(null, _value);
   }
 
+  /** Asserts that the value is true. */
+  void isTrue() {
+    Expect.equals(true, _value);
+  }
+
+  /** Asserts that the value is null. */
+  void isFalse() {
+    Expect.equals(false, _value);
+  }
+
   /** Asserts that the value has the same elements as the given collection. */
   void equalsCollection(Collection expected) {
     Expect.listEquals(expected, _value);
   }
 }
 
 /**
  * A TestSet lets you break a test suite down into a collection of classes to
  * keep things manageable. It exposes the same interface as UnitTestSuite
  * (test(), group(), expect(), etc.) but defers to a parent suite that owns it.
@@ skipping 128 matching lines @@
         </tr>""";
     if (stackTrace != null) {
       message +=
           "<tr><td></td><td colspan='2'><pre>${stackTrace}</pre></td></tr>";
     }
     fail = true;
   }
 }
 
 typedef void TestFunction();