LanguageFeatures/Extension-methods/extension_conflict_resolution_t06.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 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 that compile time error is thrown if two extension members
/// with [on] type clause are equitable and a member from the conflicting
/// extensions is referenced.
/// @author iarkh@unipro.ru



extension MyFancyList1<T> on List<T> {
  bool get isTested => false;
}

extension MyIntFancyList2<T> on List<T> {
  bool get isTested => false;
}

main() {
  List aList = [1, 2, 3];
  bool res = aList.isTested;
//                 ^
// [analyzer] unspecified
// [cfe] unspecified
}