IsNullOrEmpty on a command throws System.NullReferenceException

[craiginscotland]

When a command is not present, I should be able to reference it in the dictionary and use .IsNullOrEmpty to check for it's present. But it throws System.NullReferenceException instead.

In my case, I did not mark as optional. I used the version where I gave 2 example command lines, each with a different COMMAND perhaps that's the issue?

There is a workaround below, but I would have thought you were populate a default Object in the dictionary so that the IsNullOrEmpty could be used.

Snippet of syntax below.

[TestMethod]
public void Test_CommandLine()
{
const string USAGE = @"prog.

        Usage: prog PREPARE (--folderpath <path> | --azure --jobid <jobid> --simrun <simrun> --token <token> --host <host>)
               prog SIMIULATE --scenario <scenario_name> (--folderpath <path> | --azure --simrun <simrun> --token <token> --host <host>)";

        var opt = new Docopt();

        var arguments = opt.Apply(USAGE, "simulate --scenario senario1 --azure --simrun simrun --token token --host host");
        
        //This would crash
        if(arguments["PREPARE"].IsNullOrEmpty)
        {

        }

        //So would have to do this instead.
        if (arguments["PREPARE"] != null)
        {

        }
    }