|  | // Copyright (c) 2017, 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. | 
|  |  | 
|  | // Regression test for dart2js inference. Class.field6b should be known to be | 
|  | // potentially `null`. | 
|  |  | 
|  | import 'package:expect/expect.dart'; | 
|  |  | 
|  | class Class6 { | 
|  | var field6a; | 
|  | var field6b; | 
|  |  | 
|  | Class6() : field6a = 42 { | 
|  | field6b = field6a; | 
|  | } | 
|  | } | 
|  |  | 
|  | class SubClass6 extends Class6 { | 
|  | var field6b; | 
|  |  | 
|  | SubClass6() : field6b = 42; | 
|  |  | 
|  | get access => super.field6b; | 
|  | } | 
|  |  | 
|  | subclassField2() { | 
|  | new Class6(); | 
|  | return new SubClass6().access; | 
|  | } | 
|  |  | 
|  | main() { | 
|  | Expect.isTrue(subclassField2() == null); | 
|  | } |