Robert Nystrom
8f85a9efe4
Change-Id: I52dee4ed475611ce4ea5d0d45914717ff13f5b8b Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/141768 Auto-Submit: Bob Nystrom <rnystrom@google.com> Reviewed-by: Leaf Petersen <leafp@google.com>
58 lines
1.7 KiB
Dart
58 lines
1.7 KiB
Dart
// Copyright (c) 2019, 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 short-circuit operators do not care about the unevaluated part.
|
|
|
|
import "package:expect/expect.dart";
|
|
|
|
main() {
|
|
const c = C();
|
|
// Short-circuited operations.
|
|
// Non-taken branch of ?:.
|
|
const c1 = true ? c : c + c;
|
|
const c2 = false ? c + c : c;
|
|
// Non-taken part of &&, ||, ??.
|
|
const c3 = (c != null) || c < c;
|
|
const c4 = (c == null) && c < c;
|
|
const c5 = (c as dynamic) ?? c + c;
|
|
Expect.identical(c, c1);
|
|
Expect.identical(c, c2);
|
|
Expect.isTrue(c3);
|
|
Expect.isFalse(c4);
|
|
Expect.identical(c, c5);
|
|
// Nested short-circuiting.
|
|
const c6 = true ? c == null && c + c : c < c;
|
|
Expect.isFalse(c6);
|
|
|
|
// Concrete use-case.
|
|
Expect.equals(1, const T.length("a").value);
|
|
Expect.equals(0, const T.length("").value);
|
|
Expect.equals(0, const T.length(null).value);
|
|
Expect.equals(1, T.length([1]).value);
|
|
Expect.equals(0, T.length([]).value);
|
|
Expect.equals(0, T.length(null).value);
|
|
|
|
Expect.equals(1, const T.asserts("a").value);
|
|
Expect.equals(0, const T.asserts("").value);
|
|
Expect.equals(0, const T.asserts(null).value);
|
|
Expect.equals(1, T.asserts([1]).value);
|
|
Expect.equals(0, T.asserts([]).value);
|
|
Expect.equals(0, T.asserts(null).value);
|
|
}
|
|
|
|
class T {
|
|
final Object value;
|
|
const T(this.value);
|
|
const T.length(dynamic l) : value = (l == null ? 0 : l.length);
|
|
const T.asserts(dynamic l)
|
|
: assert(l == null || l.length < 2),
|
|
value = (l ?? "").length;
|
|
}
|
|
|
|
class C {
|
|
const C();
|
|
dynamic operator +(dynamic other) => throw "Never";
|
|
bool operator <(dynamic other) => throw "Never";
|
|
}
|