| // 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 definitions of least and greatest closure are changed in null |
| /// safe libraries to substitute [Never] in positions where previously [Null |
| /// would have been substituted, and [Object?] in positions where previously |
| /// [Object] or [dynamic] would have been substituted. |
| /// @description Check that [Object?] type is substituted for [typedef C<X> = |
| /// A<X>]. |
| /// @note Read more about the least and greatest closure test template: |
| /// https://github.com/dart-lang/co19/issues/575#issuecomment-613542349 |
| /// |
| /// @Issue 42580 |
| /// @author iarkh@unipro.ru |
| |
| import "../../../../Utils/expect.dart"; |
| |
| abstract class A<X> { |
| X get x; |
| set x(X value); |
| } |
| |
| typedef C<X> = A<X>; |
| |
| void main() { |
| void f<X>(C<X> Function() g) => g(); |
| |
| // Verify that the captured type has an `x`. |
| f(() => captureTypeArgument()..x); |
| |
| // Verify that `x` has a top type. |
| f(() => captureTypeArgument()..x = 42); |
| f(() => captureTypeArgument()..x = 'Hello'); |
| f(() => captureTypeArgument()..x = null); |
| |
| // Verify that `x` does not have type `dynamic` (but, expecting the type |
| // to be `Object?` we need the null aware access `?.`). |
| f(() => captureTypeArgument()..x?.unknownMember); |
| // ^ |
| // [analyzer] unspecified |
| // [cfe] unspecified |
| |
| // Verify that `x` has `Object` members (so it can have type `Object?`, |
| // but it cannot have type `void`). |
| f(() => captureTypeArgument()..x.toString); |
| } |