| // Copyright (c) 2020, 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 that late fields are properly reset after hot restarts. |
| |
| // Requirements=nnbd |
| |
| import 'dart:_runtime' as dart show hotRestart, resetFields; |
| |
| import 'package:expect/expect.dart'; |
| |
| late String noInitializer; |
| late int withInitializer = 1; |
| |
| class Lates { |
| static late String noInitializer; |
| static late int withInitializer = 2; |
| } |
| |
| class LatesGeneric<T> { |
| static late String noInitializer; |
| static late int withInitializer = 3; |
| } |
| |
| main() { |
| // Read this static field first to avoid interference with other reset counts. |
| var weakNullSafety = hasUnsoundNullSafety; |
| |
| // TODO(42495) `Expect.throws` contains the use of a const that triggers an |
| // extra field reset but consts are not correctly reset on hot restart so the |
| // extra reset only appears once. Perform an initial Expect.throws here to |
| // avoid confusion with the reset counts later. |
| Expect.throws(() => throw 'foo'); |
| |
| var resetFieldCount = dart.resetFields.length; |
| |
| // Set uninitialized static late fields. Avoid calling getters for these |
| // statics to ensure they are reset even if they are never accessed. |
| noInitializer = 'set via setter'; |
| Lates.noInitializer = 'Lates set via setter'; |
| LatesGeneric.noInitializer = 'LatesGeneric set via setter'; |
| |
| // Initialized statics should contain their values. |
| Expect.equals(1, withInitializer); |
| Expect.equals(2, Lates.withInitializer); |
| Expect.equals(3, LatesGeneric.withInitializer); |
| |
| // In weak null safety the late field lowering introduces a second static |
| // field that tracks if late field has been initialized thus doubling the |
| // number of expected resets. |
| // |
| // In sound null safety non-nullable fields don't require the extra static to |
| // track initialization because null is used as a sentinel value. |
| // |
| // Weak Null Safety - 12 total field resets |
| // - 3 isSet write/resets for uninitialized field writes. |
| // - 3 write/resets for the actual uninitialized field writes. |
| // - 3 isSet reads/resets for initialized field reads. |
| // - 3 reads/resets for the actual initialized field reads. |
| // |
| // Sound Null Safety - 6 total field resets: |
| // - 3 write/resets for the actual uninitialized field writes. |
| // - 3 reads/resets for the actual initialized field reads. |
| var expectedResets = |
| weakNullSafety ? resetFieldCount + 12 : resetFieldCount + 6; |
| Expect.equals(expectedResets, dart.resetFields.length); |
| |
| dart.hotRestart(); |
| resetFieldCount = dart.resetFields.length; |
| |
| // Late statics should throw on get when not initialized. |
| Expect.throws(() => noInitializer); |
| Expect.throws(() => Lates.noInitializer); |
| Expect.throws(() => LatesGeneric.noInitializer); |
| |
| // Set uninitialized static late fields again. |
| noInitializer = 'set via setter'; |
| Lates.noInitializer = 'Lates set via setter'; |
| LatesGeneric.noInitializer = 'LatesGeneric set via setter'; |
| |
| // All statics should contain their set values. |
| Expect.equals('set via setter', noInitializer); |
| Expect.equals('Lates set via setter', Lates.noInitializer); |
| Expect.equals('LatesGeneric set via setter', LatesGeneric.noInitializer); |
| Expect.equals(1, withInitializer); |
| Expect.equals(2, Lates.withInitializer); |
| Expect.equals(3, LatesGeneric.withInitializer); |
| |
| // Weak Null Safety - 12 total field resets |
| // - 3 isSet write/resets for uninitialized field writes. |
| // - 3 write/resets for the actual uninitialized field writes. |
| // - 3 isSet reads/resets for initialized field reads. |
| // - 3 reads/resets for the actual initialized field reads. |
| // Sound Null Safety - 6 total field resets: |
| // - 3 write/resets for the actual uninitialized field writes. |
| // - 3 reads/resets for the actual initialized field reads. |
| expectedResets = weakNullSafety ? resetFieldCount + 12 : resetFieldCount + 6; |
| Expect.equals(expectedResets, dart.resetFields.length); |
| |
| dart.hotRestart(); |
| dart.hotRestart(); |
| resetFieldCount = dart.resetFields.length; |
| |
| // Late statics should throw on get when not initialized. |
| Expect.throws(() => noInitializer); |
| Expect.throws(() => Lates.noInitializer); |
| Expect.throws(() => LatesGeneric.noInitializer); |
| |
| // Initialized statics should contain their values. |
| Expect.equals(1, withInitializer); |
| Expect.equals(2, Lates.withInitializer); |
| Expect.equals(3, LatesGeneric.withInitializer); |
| |
| // Weak Null Safety - 9 total field resets: |
| // - 3 isSet reads/resets for uninitialized field reads. |
| // - 3 isSet reads/resets for initialized field reads. |
| // - 3 reads/resets for the actual initialized field reads. |
| // |
| // Sound Null Safety - 6 total field resets: |
| // - 3 reads/resets for actual uninitialized field reads. |
| // - 3 reads/resets for the actual initialized field reads. |
| expectedResets = weakNullSafety ? resetFieldCount + 9 : resetFieldCount + 6; |
| Expect.equals(expectedResets, dart.resetFields.length); |
| } |