// 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.

// @dart = 2.9

/// @assertion If more than one extension applies to a specific member
/// invocation, then we resort to a heuristic to choose one of the extensions to
/// apply. If exactly one of them is "more specific" than all the others, that
/// one is chosen. Otherwise it is a compile-time error.
///
/// An extension with [on] type clause [T1] is more specific than another
/// extension with [on] type clause [T2] iff
///
///   1. The latter extension is declared in a platform library, and the former
///      extension is not
///   2. they are both declared in platform libraries or both declared in
///      non-platform libraries, and
///   3. the instantiated type (the type after applying type inference from the
///      receiver) of [T1] is a subtype of the instantiated type of [T2] and
///      either
///   4. not vice versa, or
///   5. the instantiate-to-bounds type of [T1] is a subtype of the
///      instantiate-to-bounds type of [T2] and not vice versa.
///
/// @description Check "more specific" resolving algorithm
/// @author sgrekhov@unipro.ru

class A {}
class B {}
class C extends A {}

extension ExtA<T extends A> on List<T> {
  String method() => "ExtA method";
}

extension ExtC<T extends C> on List<T> {
  String method() => "ExtC method";
}

main() {
  List<B> list = [new B(), new B()];
  list.method();
//     ^
// [analyzer] unspecified
// [cfe] unspecified
}