| // Copyright (c) 2021, 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. |
| |
| /** |
| * @assertion If a class [C] in an opted-in library implements the same generic |
| * class [I] more than once as [I0], .., [In], and at least one of the [Ii] is |
| * not syntactically equal to the others, then it is an error if |
| * [NNBD_TOP_MERGE(S0, ..., Sn)] is not defined where [Si] is [NORM(Ii)]. |
| * Otherwise, for the purposes of runtime subtyping checks, [C] is considered to |
| * implement the canonical interface given by [NNBD_TOP_MERGE(S0, ..., Sn)]. |
| * |
| * @description Check that that the result of NNBD_TOP_MERGE(Object, Object)] is |
| * [Object] in weak mode. |
| * |
| * Dynamic type checks with unsound null checking erases `?` from types and add |
| * `*` (recursively, so `List<int?>?` becomes `List<int*>*`). In particular |
| * `LEGACY_SUBTYPE(Object Function(Object), Object? Function(Object?))` is true. |
| * |
| * @author iarkh@unipro.ru |
| */ |
| // Requirements=nnbd-weak |
| |
| import "../../../../Utils/expect.dart"; |
| |
| class B extends CHECK_TOP_MERGE<Object> {} |
| class C extends CHECK_TOP_MERGE<Object> {} |
| |
| class D extends B implements C {} |
| |
| void main() { |
| Expect.isTrue(D().f is Object Function(Object)); |
| Expect.isTrue(D().f is Object? Function(Object?)); |
| } |
