LanguageFeatures/nnbd/late_A05_t03.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 read of a field or variable which is marked as late which has
/// not yet been written to causes the initializer expression of the variable to
/// be evaluated to a value, assigned to the variable or field, and returned as
/// the value of the read.
/// ...
/// If a variable or field is read from during the process of evaluating its own
/// initializer expression, and no write to the variable has occurred, the read
/// is treated as a first read and the initializer expression is evaluated again.
///
/// @description Check that if a variable or field is read from during the
/// process of evaluating its own initializer expression but write to the
/// variable occurred, then initializer expression is not evaluated again
/// @author sgrekhov@unipro.ru

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

String _log = "";
int _counter = 0;

String init(String val1, String val2, void writeAndReadme()) {
  _counter++;
  _log = "counter: $_counter";
  if (_counter == 1) {
    writeAndReadme();
    return val2;
  }
  return val1;
}

void clear() {
  _log = "";
  _counter = 0;
}

class C {
  static late String s =
      init("No woman", "no cry", (){C.s = "Lily was here"; C.s;});
}

late String g =
      init("No woman", "no cry", (){g = "Lily was here"; g;});

main() {
  Expect.equals("", _log);
  Expect.equals("no cry", C.s);
  Expect.equals("counter: 1", _log);
  clear();

  Expect.equals("no cry", g);
  Expect.equals("counter: 1", _log);
}