LanguageFeatures/Extension-methods/explicit_extension_member_invocation_A12_t01.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 A simple member invocation on a target expression X is an
/// expression of one of the forms:
/// Member invocation on target X	     Corresponding member name
///        X[expr2] = expr3                        []=
/// @description Check explicit extension member invocation in form of
/// X[expr2] = expr3
/// @author sgrekhov@unipro.ru


import "../../Utils/expect.dart";

class C {
  String value = "";
  void operator []=(int index, String value) {
    this.value = "C:$value:$index";
  }
}

extension Extension1 on C {
  void operator []=(int index, String value) {
    this.value = "Extension1:$value:$index";
  }
}

extension Extension2 on C {
  void operator []=(int index, String value) {
    this.value = "Extension2:$value:$index";
  }
}

main() {
  C c = new C();
  Extension1(c)[42] = "Lily was here";
  Expect.equals("Extension1:Lily was here:42", c.value);
  Extension2(c)[41] = "Show must go on";
  Expect.equals("Extension2:Show must go on:41", c.value);
  c[40] = "Let it be";
  Expect.equals("C:Let it be:40", c.value);
}