blob: 4d40b885f7a1832c90a99866b1b9d3f2df1119e7 [file] [log] [blame]
// 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.
// @dart = 2.9
// Evaluation of an if-null expression e of the form e1 ?? e2 is equivalent to
// the evaluation of the expression ((x) => x == null ? e2 : x)(e1).
//
// Therefore, e1 should be evaluated first; if it is non-null, e2 should not
// be evaluated.
import "package:expect/expect.dart";
bad() {
throw new Exception();
}
bool firstExecuted = false;
first() {
firstExecuted = true;
return null;
}
second() {
Expect.isTrue(firstExecuted);
return 2;
}
main() {
Expect.equals(1, 1 ?? bad());
Expect.equals(2, first() ?? second());
}