LanguageFeatures/nnbd/null_aware_operator_A16_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 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]
 *  ]
 * @author sgrekhov@unipro.ru
 */
// Requirements=nnbd-strong
import "../../Utils/expect.dart";

class C {
  int c1 = 0, c2 = 0;
  String get log => "test1 called $c1 times, test2() called $c2 times";

  String get test1 {
    c1++;
    return "Show must go on";
  }

  String test2() {
    c2++;
    return "Let it be";
  }
}

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

  var actual1 = c1 .. test1;
  var expected = c1;
  Expect.equals(expected, actual1);
  Expect.equals("test1 called 1 times, test2() called 0 times", c1.log);

  var actual2 = c1 .. test2();
  Expect.equals(expected, actual2);
  Expect.equals("test1 called 1 times, test2() called 1 times", c1.log);

  var actual3 = c1 .. test1 .. test2();
  Expect.equals(expected, actual3);
  Expect.equals("test1 called 2 times, test2() called 2 times", c1.log);

  C? c2 = new C();
  if (c2 != null) {
    var actual4 = c2 .. test1;
    var expected2 = c2;
    Expect.equals(expected2, actual4);
    Expect.equals("test1 called 1 times, test2() called 0 times", c2.log);

    var actual5 = c2 .. test2();
    Expect.equals(expected2, actual5);
    Expect.equals("test1 called 1 times, test2() called 1 times", c2.log);

    var actual6 = c2 .. test1 .. test2();
    Expect.equals(expected2, actual6);
    Expect.equals("test1 called 2 times, test2() called 2 times", c2.log);
  }
}