| // Copyright (c) 2018, 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. |
| |
| // Tests how nullability is inferred for a final field which is implicitly |
| // initialized to null. This is a regression test for |
| // https://github.com/flutter/flutter/issues/21957. |
| |
| // VMOptions=--no_background_compilation --optimization_counter_threshold=10 |
| |
| import "package:expect/expect.dart"; |
| |
| class A {} |
| |
| class X { |
| final A f; |
| X.empty() : f = null; |
| X.full() : f = A(); |
| } |
| |
| bool doit(bool choice) { |
| X x = choice ? X.full() : X.empty(); |
| return x.f == null; |
| } |
| |
| class Y { |
| final A f; |
| Y.c0() : f = A(); |
| Y.c1() : f = null; |
| Y.c2() : f = A(); |
| } |
| |
| bool doit2(int choice) { |
| Y y; |
| switch (choice) { |
| case 0: |
| y = new Y.c0(); |
| break; |
| case 1: |
| y = new Y.c1(); |
| break; |
| case 2: |
| y = new Y.c2(); |
| break; |
| } |
| return y.f == null; |
| } |
| |
| void main() { |
| for (int i = 0; i < 100; i++) { |
| bool ping = (i & 1) == 0; |
| bool result = doit(ping); |
| Expect.equals(result, !ping); |
| |
| bool result2 = doit2(i % 3); |
| Expect.equals(result2, (i % 3) != 0 && (i % 3) != 2); |
| } |
| } |