dart-sdk/tests/web/is_check_instanceof_test.dart
Sigmund Cherem 912005267d [web] rename suite dart2js -> web.
Change-Id: I46be49b2effec3e38a3dc44cd45cfe736f77fa78
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/182680
Commit-Queue: Sigmund Cherem <sigmund@google.com>
Reviewed-by: Joshua Litt <joshualitt@google.com>
Reviewed-by: Nicholas Shahan <nshahan@google.com>
Reviewed-by: Stephen Adams <sra@google.com>
2021-02-04 23:11:32 +00:00

75 lines
2.6 KiB
Dart

// Copyright (c) 2015, 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.
import "package:expect/expect.dart";
// It is sometimes possible to compile is-checks to 'instanceof', when the class
// is not in an 'implements' clause or used as a mixin.
// This test verifies is-checks work with simple classes that have various
// degrees of instantiation.
class INSTANTIATED {} // instantiated and used in many ways
class DEFERRED {} // instantiated after first check
class UNUSED {} // used only in is-check
class REMOVED {} // allocated but optimized out of program
class DEFERRED_AND_REMOVED {} // allocated after first check and removed
class USED_AS_TYPE_PARAMETER {} // only used as a type parameter
class USED_AS_TESTED_TYPE_PARAMETER {} // only used as a type parameter
class Check<T> {
bool check(x) => x is T;
}
class Check2<T> {
bool check(x) => x is USED_AS_TYPE_PARAMETER;
}
void main() {
var things = []..length = 3;
things.setRange(0, 3, [new INSTANTIATED(), 1, new Object()]);
var checkX = new Check<INSTANTIATED>();
var checkU1 = new Check<USED_AS_TESTED_TYPE_PARAMETER>();
var checkU2 = new Check<USED_AS_TYPE_PARAMETER>();
var removed = new REMOVED(); // This is optimized out.
// Tests that can be compiled to instanceof:
Expect.isTrue(things[0] is INSTANTIATED);
Expect.isFalse(things[1] is INSTANTIATED);
Expect.isFalse(things[1] is REMOVED);
Expect.isFalse(things[1] is DEFERRED_AND_REMOVED);
Expect.isFalse(things[1] is DEFERRED);
// Tests that might be optimized to false since there are no allocations:
Expect.isFalse(things[1] is UNUSED);
Expect.isFalse(things[1] is USED_AS_TYPE_PARAMETER);
Expect.isTrue(checkX.check(things[0]));
Expect.isFalse(checkX.check(things[1]));
Expect.isFalse(checkU1.check(things[1]));
Expect.isFalse(checkU2.check(things[1]));
var removed2 = new DEFERRED_AND_REMOVED(); // This is optimized out.
// First allocation of DEFERRED is after the above tests.
things.setRange(0, 3, [new INSTANTIATED(), 1, new DEFERRED()]);
// Tests that can be compiled to instanceof:
Expect.isTrue(things[0] is INSTANTIATED);
Expect.isFalse(things[1] is INSTANTIATED);
Expect.isFalse(things[1] is REMOVED);
Expect.isFalse(things[1] is DEFERRED_AND_REMOVED);
Expect.isFalse(things[1] is DEFERRED);
Expect.isTrue(things[2] is DEFERRED);
// Tests that might be optimized to false since there are no allocations:
Expect.isFalse(things[1] is UNUSED);
Expect.isFalse(things[1] is USED_AS_TYPE_PARAMETER);
}