Ensure that hashCode and runtimeType work on null.

tests/corelib/null.dart

+// Copyright (c) 2012, 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.
+
+// Test that Null inherits properties from Object.
+
+main() {
+  var x;
+  // These shouldn't throw.
+  x.runtimeType;
+  x.toString();
+  x.hashCode();
+
+  // operator== is inherited from Object. It's the same as identical.
+  // That's not really testable.
+  Expect.isTrue(identical(x, null));
+  Expect.isTrue(x == null);
+
+  // noSuchMethod must throw a NullPointerException.
+  Expect.throws(() => x.noSuchMethod(), (e) => e is NullPointerException);
+  Expect.throws(() => x.notThere(), (e) => e is NullPointerException);
+
+  // Methods can be closurized.
+  // var nsm = null.noSuchMethod;

[kasperl, 2012/09/27 08:09:38]

File a bug for this?

[Lasse Reichstein Nielsen, 2012/09/27 09:32:35]

Done. And the code should have been uncommented.

+  // Expect.throws(nsm, (e) => e is NullPointerException);
+  var hc = x.hashCode;
+  Expect.equals(hc(), null.hashCode());

[kasperl, 2012/09/27 08:09:38]

What's the expected? I guess null.hashCode() and null.toString() are the
expected results so they so should go before the actual value (parameter order).

[Lasse Reichstein Nielsen, 2012/09/27 09:32:35]

Good point, yes they were intended as expectations,.

+  var ts = x.toString;
+  Expect.equals(ts(), null.toString());
+}