blob: ba598006f3b820b110b7b0c4e54c3f8b66c58a2a [file] [log] [blame]
// 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 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(FutureOr<FutureOr>,
/// FutureOr<FutureOr>)] is [FutureOr<FutureOr>].
/// @author
// Requirements=nnbd-strong
import "dart:async";
import "../../../Utils/expect.dart";
class B extends CheckTopMerge<FutureOr<FutureOr>> {}
class C extends CheckTopMerge<FutureOr<FutureOr>> {}
class D extends B implements C {}
void main() {
Expect.isTrue(D().f is FutureOr<FutureOr> Function(FutureOr<FutureOr>));
Expect.runtimeIsType<FutureOr<FutureOr> Function(FutureOr<FutureOr>)>(D().f);