mirror of
https://github.com/dart-lang/sdk
synced 2024-11-05 18:22:09 +00:00
a719910d78
Interesting bits: - Removed some behavior that is now unreachable in the presence of type errors. - Made if_null_behavior_test not a multitest since it doesn't need to be any more. - Likewise, if_null_evaluation_order_test never needed to be a multitest. R=lrn@google.com Review-Url: https://codereview.chromium.org/3003933002 .
40 lines
1.7 KiB
Dart
40 lines
1.7 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.
|
|
|
|
// Verify that '??' binds tighter than '?:' and less tightly than '||'.
|
|
|
|
import "package:expect/expect.dart";
|
|
|
|
main() {
|
|
// Make sure the "none" test fails if "??" is not implemented. This makes
|
|
// status files easier to maintain.
|
|
var _ = null ?? null;
|
|
|
|
// "a ?? b ?? c" should be legal, and should evaluate to the first non-null
|
|
// value (or null if there are no non-null values).
|
|
Expect.equals(1, 1 ?? 2 ?? 3);
|
|
Expect.equals(2, null ?? 2 ?? 3);
|
|
Expect.equals(3, null ?? null ?? 3);
|
|
Expect.equals(null, null ?? null ?? null);
|
|
|
|
// "a ?? b ? c : d" should parse as "(a ?? b) ? c : d", therefore provided
|
|
// that a is true, b need not be a bool. An incorrect parse of
|
|
// "a ?? (b ? c : d)" would require b to be a bool to avoid a static type
|
|
// warning.
|
|
Expect.equals(2, true ?? 1 ? 2 : 3);
|
|
|
|
// "a ?? b || c" should parse as "a ?? (b || c)", therefore it's a static
|
|
// type warning if b doesn't have type bool. An incorrect parse of
|
|
// "(a ?? b) || c" would allow b to have any type provided that a is bool.
|
|
false ?? 1 || true; //# 06: compile-time error
|
|
|
|
// "a || b ?? c" should parse as "(a || b) ?? c", therefore it is a static
|
|
// type warning if b doesn't have type bool. An incorrect parse of
|
|
// "a || (b ?? c)" would allow b to have any type provided that c is bool.
|
|
false || 1 ?? true; //# 07: compile-time error
|
|
|
|
// An incorrect parse of "a || (b ?? c)" would result in no checked-mode
|
|
// error.
|
|
Expect.throwsAssertionError(() => false || null ?? true);
|
|
}
|