| // Copyright (c) 2020, 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 Members inherited in a class in an opted-in library, which are |
| * inherited via a class or mixin defined in a legacy library are viewed with |
| * their erased legacy signature, even if they were original defined in an |
| * opted-in library. Note that if a class which is defined in a legacy library |
| * inherits a member with the same name from multiple super-interfaces, then |
| * error checking is done as usual using the legacy typing rules which ignore |
| * nullability. This means that it is valid for a legacy class to inherit the |
| * same member signature with contradictory nullability information. For the |
| * purposes of member lookup within a legacy library, nullability information is |
| * ignored, and so it is valid to simply erase the nullability information |
| * within the legacy library. When referenced from an opted-in library, the same |
| * erasure is performed, and the member is seen at its legacy type. |
| * |
| * We use legacy subtyping when checking inherited member signature coherence in |
| * classes because opted out libraries may bring together otherwise incompatible |
| * member signatures without causing an error. |
| * |
| * @description Check that legacy class can inherit the same field from two |
| * opted in classes with contradictory nullability information. |
| * |
| * @author iarkh@unipro.ru |
| */ |
| // Requirements=nnbd-weak |
| |
| import "../../../../Utils/expect.dart"; |
| import "override_checking_A03_opted_out_lib.dart"; |
| |
| main() { |
| LEGACY_FIELDS_1 x1 = LEGACY_FIELDS_1(); |
| Expect.isNull(x1.i); |
| Expect.isNull(x1.o); |
| Expect.isNull(x1.f); |
| |
| LEGACY_FIELDS_2 x2 = LEGACY_FIELDS_2(); |
| x2.i = null; |
| Expect.isNull(x2.i); |
| x2.o = null; |
| Expect.isNull(x2.o); |
| x2.f = null; |
| Expect.isNull(x2.f); |
| } |