using System;

​

class Foo

{

    private readonly bool _enabled;

    public Foo() { _enabled = int.IsEvenInteger(System.DateTime.Now.Millisecond); }

    public bool Enabled() => _enabled;

}

​

public class Program

{

    private static string Test(bool left, bool right)

        => (left == right ? "Passed" : "Failed");

    public static void Main()

    {

        Console.WriteLine("Hello, Zbyněk Novotný!");

        Console.WriteLine("https://github.com/ThreeMammals/Ocelot/pull/1684#discussion_r1293789996");

​

        Foo[] variants = new Foo[] { null, new Foo() };

        for (int i = 0; i < variants.Length; i++)

        {

            Foo options = variants[i];

            Console.WriteLine($"\nTest {i + 1}: options is " + (options == null ? "null" : "not null"));

            Console.WriteLine($"  Old expression: options == null || !options.Enabled();");

            bool old = options == null || !options.Enabled();

            Console.WriteLine($"    Value is {old}");

​

            Console.WriteLine($"  New expression 1: !(options?.Enabled() ?? false);");

            bool ex1 = !(options?.Enabled() ?? false);

            Console.WriteLine($"    Value is {ex1}");

            Console.WriteLine("    " + Test(old, ex1));

​

            Console.WriteLine($"  New expression 2: options?.Enabled() != true;");

            bool ex2 = options?.Enabled() != true;

            Console.WriteLine($"    Value is {ex2}");

            Console.WriteLine("    " + Test(old, ex2));

        }

    }

}

​