// Copyright (c) 2011, 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

/// @assertion double log(num x)
/// Returns NaN if [x] is NaN or less than zero.
/// @description Checks that [log] returns NaN if [x] is NaN or less than zero.
/// @author msyabro
/// @reviewer pagolubev


import "dart:math" as Math;
import "../../Utils/expect.dart";

main() {
  Expect.isTrue(Math.log(-1).isNaN);
  Expect.isTrue(Math.log(-0.5).isNaN);
  Expect.isTrue(Math.log(double.nan).isNaN);
  Expect.isTrue(Math.log(double.negativeInfinity).isNaN);
}