LanguageFeatures/nnbd/static_errors_A11_t04.dart

/*
 * Copyright (c) 2019, 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 For the purposes of errors and warnings, the null aware operators
 * ?., ?.., and ?.[] are checked as if the receiver of the operator had
 * non-nullable type. More specifically, if the type of the receiver of a null
 * aware operator is T, then the operator is checked as if the receiver had type
 * NonNull(T).
 *
 * @description Check that if the type of the receiver of a null aware operator
 * is T, then the operator is checked as if the receiver had type NonNull(T).
 * Test Function?
 * @issue 38715
 * Language @issue https://github.com/dart-lang/language/issues/711
 * @author sgrekhov@unipro.ru
 */
// SharedOptions=--enable-experiment=non-nullable
// Requirements=nnbd-strong
typedef void Foo();

void foo() {}

main() {
  Function? f1 = foo;
  f1?.toString();
  f1 ?.. toString();

  Foo? f2 = foo;
  f2?.toString();
  f2 ?.. toString();
}