Test implicit this on fields.

dart/tests/language/src/ImplicitThisTest.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.
+
+interface Interface {
+  final x;
+}
+
+class Abstract implements Interface {
+  String toString() => x.toString();
+}
+
+class Concrete extends Abstract {
+  get x() => 7;
+}
+
+class SubConcrete extends Concrete {
+  final x;
+  SubConcrete(this.x);
+}
+
+void main() {
+  var x = new Abstract(); /// 01: static type error

[gbracha, 2011/11/02 19:01:45]

Why do you expect a static warning here? Class Abstract is a concrete class. It
does not declare an abstract method. What I would expect would be a static
warning on the declaration of Abstract, saying that it does not in fact
implement the getter x of Interface. Mind you, it looks like the spec doesn't 
make this clear.   We should implement the abstract modifier for classes as well
to make al this run smoothly.

[ahe, 2011/11/02 19:03:57]

Good point. I should add the abstract keyword to the class Abstract.

+  Expect.equals(x, x);
+  Expect.equals(new Concrete().toString(), '7');
+  Expect.equals(new SubConcrete(42).toString(), '42');
+  Expect.equals(new SubConcrete(new Concrete()).toString(), '7');
+}