LanguageFeatures/nnbd/null_aware_operator_A16_t04.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 cascade expression e..s translates as follows, where F is the
 * translation of e and x and y are fresh object level variables:
 *  fn[k : Exp -> Exp] : Exp =>
 *      F[fn[r : Exp] : Exp => let x = r in
 *                             let y = EXP(x.s)
 *                             in k[x]
 *  ]
 *
 * @description Check that a cascade expression e..s translates as follows,
 * where F is the translation of e and x and y are fresh object level variables:
 *  fn[k : Exp -> Exp] : Exp =>
 *      F[fn[r : Exp] : Exp => let x = r in
 *                             let y = EXP(x.s)
 *                             in k[x]
 *  ]
 * Test cascade assignment
 * @author sgrekhov@unipro.ru
 */
// Requirements=nnbd-strong
import "../../Utils/expect.dart";

class C {
  String test1 = "Lily was here";
  String _test2 = "";
  void set test2(String val) {
    _test2 = val;
  }
}

main() {
  C c1 = new C();

  var actual1 = c1 .. test1 = "Show must go on";
  var expected = c1;
  Expect.equals(expected, actual1);
  Expect.equals("Show must go on", c1.test1);

  var actual2 = c1 .. test2 = "Show must go on";
  Expect.equals(expected, actual2);
  Expect.equals("Show must go on", c1._test2);

  var actual3 = c1
    .. test1 = "Let it be"
    .. test2 = "Let it be";
  Expect.equals(expected, actual3);
  Expect.equals("Let it be", c1.test1);
  Expect.equals("Let it be", c1._test2);

  C? c2 = new C();
  if (c2 != null) {
    var actual4 = c2 .. test1 = "Show must go on";
    var expected2 = c2;
    Expect.equals(expected2, actual4);
    Expect.equals("Show must go on", c2.test1);

    var actual5 = c2 .. test2 = "Show must go on";
    Expect.equals(expected2, actual5);
    Expect.equals("Show must go on", c2._test2);

    var actual6 = c2
      .. test1 = "Let it be"
      .. test2 = "Let it be";
    Expect.equals(expected2, actual6);
    Expect.equals("Let it be", c2.test1);
    Expect.equals("Let it be", c2._test2);
  }
}