// Copyright (c) 2018, 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

class Supertype {
  factory Supertype() = X;
  factory Supertype() = X;
//        ^^^^^^^^^
// [analyzer] COMPILE_TIME_ERROR.DUPLICATE_CONSTRUCTOR
//        ^
// [cfe] 'Supertype' is already declared in this scope.
}

class X implements Supertype {
  X();
}

main() {
  X x = new Supertype();
  //        ^
  // [cfe] Can't use 'Supertype' because it is declared more than once.
}