| // Copyright (c) 2018, 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"; |
| |
| class I0 {} |
| |
| class A {} |
| |
| class B extends A implements I0 {} |
| |
| class B2 extends A {} |
| |
| class C { |
| void f(B x) {} |
| } |
| |
| abstract class I { |
| void f(covariant A x); |
| } |
| |
| // This class contains a forwarding stub for f to allow it to satisfy the |
| // interface I, while still ensuring that the x argument is type checked before |
| // C.f is executed. |
| // |
| // Super calls in a derived class resolve directly to C.f, and are type checked |
| // accordingly at compile time. |
| class D extends C implements I {} |
| |
| class E extends D { |
| void test() { |
| I0 i0 = null; |
| B2 b2 = null; |
| |
| // ok since I0 is assignable to B |
| super.f(i0); //# 01: ok |
| |
| // not ok since B2 is not assignable to B |
| super.f(b2); //# 02: compile-time error |
| |
| var superF = super.f; // Inferred type: (B) -> void |
| |
| // ok since I0 is assignable to B |
| superF(i0); //# 03: ok |
| |
| // not ok since B2 is not assignable to B |
| superF(b2); //# 04: compile-time error |
| |
| // Should pass since superF's runtime type is (B) -> void |
| Expect.isTrue(superF is void Function(B)); //# 05: ok |
| Expect.isTrue(superF is! void Function(I0)); //# 05: continued |
| Expect.isTrue(superF is! void Function(A)); //# 05: continued |
| Expect.isTrue(superF is! void Function(Object)); //# 05: continued |
| } |
| } |
| |
| main() { |
| new E().test(); |
| } |