Support "Or" Argument

[tdashworth]

Would it be possible to support two (or more?) optional arguments that together must be required. For example:

dotnet clean <PROJECT>|<SOLUTION>

where you must pass either a project or a solution. It this case they would be the same type FileInfo but I'm looking for a FileInfo and string.

Otherwise is it possible to setup two commands? One clitool subcommand1 <string-arg> and another clitool subcommand1 <file-arg>?

[jonsequitur]

You can do this with a ParseArgument<T> delegate, for example:

public class FileInfoOrString
{
    public FileInfoOrString(FileInfo fileInfo) => FileInfoArg = fileInfo;
    public FileInfoOrString(String s) => StringArg = s;
    public FileInfo FileInfoArg {  get; }
    public String StringArg {  get; }
}

var root = new RootCommand
{
    new Argument<FileInfoOrString>("FileInfo|String", parse: argResult => {
        var arg = argResult.Tokens.Single().Value;
        if (File.Exists(arg))
        {
            return new FileInfoOrString(new FileInfo(arg));
        } 

        return new FileInfoOrString(arg);
    })
};

[tdashworth]

Thanks! Exactly what I need 😀

[tdashworth]

I was struggling to use the argument name "FileInfo|String" and for it to bind to the command handler. I have made a PR for a small change to replace the "|" with "or" so that it allows a friendlier parameter name to the handler.