| // 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 The flatten function is modified as follows: |
| /// |
| /// [flatten(T)] is defined by cases on [T]: |
| /// |
| /// if [T] is [S?] then [flatten(T) = flatten(S)?] |
| /// otherwise if [T] is [S*] then [flatten(T) = flatten(S)*] |
| /// otherwise if [T] is [FutureOr<S>] then [flatten(T) = S] |
| /// otherwise [if T <: Future] then let [S] be a type such that [T <: |
| /// Future<S>] and for all [R], if [T <: Future<R>] then [S <: R]; then |
| /// [flatten(T) = S] |
| /// otherwise [flatten(T) = T] |
| /// |
| /// @description Check that future flattening works correctly for |
| /// [Future<Object>] type statically and the expression cannot be null. |
| /// |
| /// @Issue 41339, 41340 |
| /// @author iarkh@unipro.ru |
| |
| |
| import "dart:async"; |
| |
| main() { |
| Future<Future<Object>>(() => Future<Object?>(() => null)); |
| // ^ |
| // [analyzer] unspecified |
| // [cfe] unspecified |
| |
| } |
