blob: fee63dad5afdcf4216ab3d28276c8a95f6090362 [file] [log] [blame]
// 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;
// The first call of `Expect.throws` involves type tests that initialize
// values in the runtime type system that will read static fields. After
// initialization fields are never read again (even after a hot restart)
// so we perform the first call here before we start counting field resets.
Expect.throws(() => throw 'foo');
dart.hotRestart();
// Count the number of reset fields triggered by a call to `Expect.throws`
// after every hot restart. This value is used as an offset in expectations
// below. (Update the expectation below if the number changes.)
Expect.throws(() => throw 'foo');
var expectThrowsResetFieldCount = dart.resetFields.length;
Expect.equals(0, expectThrowsResetFieldCount);
dart.hotRestart();
// 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 ? 12 : 6;
Expect.equals(expectedResets, dart.resetFields.length);
dart.hotRestart();
// 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
? expectThrowsResetFieldCount + 12
: expectThrowsResetFieldCount + 6;
Expect.equals(expectedResets, dart.resetFields.length);
dart.hotRestart();
dart.hotRestart();
// 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
? expectThrowsResetFieldCount + 9
: expectThrowsResetFieldCount + 6;
Expect.equals(expectedResets, dart.resetFields.length);
}