tests/language/implicit_this_test.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.

import "package:expect/expect.dart";

abstract class Interface {
  final x;
}

abstract class Abstract implements Interface {
  String toString() => x.toString();
}

// This class does not implement "x" either, but it is not marked
// abstract.
class SubAbstract1 extends Abstract { } /// 01: static type warning

// This class is implicitly abstract as it declares an abstract getter
// method.
class SubAbstract2 extends Abstract {
  get x;  // Abstract.
}

// This class does not implement "x" either, but it is not marked
// abstract.
class SubSubAbstract2 extends SubAbstract2 { } /// 04: static type warning

class Concrete extends Abstract {
  get x => 7;
}

class SubConcrete extends Concrete {
  final x;
  SubConcrete(this.x);
}

void main() {
  var x = new Abstract(); /// 02: runtime error
  var y = new SubAbstract1(); /// 01: continued
  var z = new SubAbstract2();
  var a = new SubSubAbstract2(); /// 04: continued
  Expect.equals(x, x); /// 02: continued
  Expect.equals('7', new Concrete().toString());
  Expect.equals('42', new SubConcrete(42).toString());
  Expect.equals('7', new SubConcrete(new Concrete()).toString());
}