dart-sdk/tests/language/implicit_downcast_during/null_aware_method_invocation_test.dart
Paul Berry e933e91aaa Reland "Flow analysis: promote to non-nullable on initialization"
This is a reland of 6a1c54ec30

Original change's description:
> Flow analysis: promote to non-nullable on initialization
>
> When flow analysis encounters a variable declaration of the form `T? x
> = expr;`, if the type of `expr` is `T`, then the variable is
> immediately promoted to type `T`.
>
> Fixes #43099.
>
> Change-Id: Ia206fe0d50e2fdd9bdf637e13c85633d8490dbcc
> Bug: https://github.com/dart-lang/sdk/issues/43099
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/163841
> Commit-Queue: Paul Berry <paulberry@google.com>
> Reviewed-by: Bob Nystrom <rnystrom@google.com>
> Reviewed-by: Johnni Winther <johnniwinther@google.com>
> Reviewed-by: Konstantin Shcheglov <scheglov@google.com>

Bug: https://github.com/dart-lang/sdk/issues/43099
Change-Id: I7530bb0f7c24674a7b500558b89d50b35e045aca
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/166305
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Commit-Queue: Paul Berry <paulberry@google.com>
2020-10-07 13:14:55 +00:00

21 lines
492 B
Dart

// Copyright (c) 2017, 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.
class A {}
class B extends A {}
class C {
void f(B b) {}
}
main() {
var c = new C() as C?;
A a = new B();
c?.f(a);
// ^
// [analyzer] COMPILE_TIME_ERROR.ARGUMENT_TYPE_NOT_ASSIGNABLE
// [cfe] The argument type 'A' can't be assigned to the parameter type 'B'.
}