| /* |
| * 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, and no write to the |
| * variable has occurred, the read is treated as a first read and the |
| * initializer expression is evaluated again |
| * @author sgrekhov@unipro.ru |
| */ |
| // SharedOptions=--enable-experiment=non-nullable |
| import "../../Utils/expect.dart"; |
| |
| String _log = ""; |
| int _counter = 0; |
| |
| String init(String val, void readme()) { |
| _counter++; |
| _log = "init('$val'), counter: $_counter"; |
| if (_counter == 1) { |
| readme(); |
| throw new Exception(); |
| } |
| return val; |
| } |
| |
| void clear() { |
| _counter = 0; |
| } |
| |
| class C { |
| covariant late String v1; |
| late final String v2; |
| late String v3; |
| |
| C() : v1 = init("Lily", (){this.v1;}), |
| v2 = init("was", (){this.v2;}), |
| v3 = init("here", (){this.v3;}); |
| } |
| |
| main() { |
| C c = new C(); |
| Expect.equals("", _log); |
| |
| Expect.throws(() {c.v1;}); |
| Expect.equals("Lily", c.v1); |
| Expect.equals("init('Lily'), counter: 2", _log); |
| clear(); |
| |
| Expect.throws(() {c.v2;}); |
| Expect.equals("was", c.v2); |
| Expect.equals("init('was'), counter: 2", _log); |
| clear(); |
| |
| Expect.throws(() {c.v3;}); |
| Expect.equals("here", c.v3); |
| Expect.equals("init('here'), counter: 2", _log); |
| } |