MissingRequiredOptionError when specifying required Value after enumerable Options

[ericnewton76]

Issue by SuperFXMaster
Tuesday Oct 11, 2016 at 19:24 GMT
Originally opened as gsscoder/commandline#361

---

The following options class:

public class CommandLineOptions
{
    [Value(0, Required = true)]
    public string InputFileName { get; set; }

    [Option('o', "output")]
    public string OutputFileName { get; set; }

    [Option('i', "include", Separator = ',')]
    public IEnumerable<string> Included { get; set; }

    [Option('e', "exclude", Separator = ',')]
    public IEnumerable<string> Excluded { get; set; }
}

When provided to the default parser, with the commandline app.exe --exclude=a,b InputFile.txt results in a MissingRequiredOptionError: A required value not bound to option name is missing. I expected the library to accept InputFileName = InputFile.txt and --exclude=a,b as Excluded = { "a", "b" }. Is there something else required to make this work as I expect, or is it a bug?

[ericnewton76]

Comment by nemec
Tuesday Oct 11, 2016 at 19:57 GMT

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Yes, I think that's a bug. If you set Required=false you'll see that a, b, and InputFile.txt are all part of Included. Additionally, the "EnableDashDash" setting doesn't work either:

void Main()
{
    var p = new Parser(s =>
    {
        s.EnableDashDash = true;
    });
    var result = p.ParseArguments<CommandLineOptions>("--exclude=a,b -- InputFile.txt".Split());
    result.WithNotParsed(e => e.Dump());
    result.WithParsed(d => d.Dump());
}

public class CommandLineOptions
{
    [Value(0, Required = true)]
    public string InputFileName { get; set; }

    [Option('o', "output")]
    public string OutputFileName { get; set; }

    [Option('i', "include", Separator = ',')]
    public IEnumerable<string> Included { get; set; }

    [Option('e', "exclude", Separator = ',')]
    public IEnumerable<string> Excluded { get; set; }
}

[ericnewton76]

Comment by SuperFXMaster
Wednesday Oct 12, 2016 at 16:20 GMT

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As a workaround, the commandline --exclude=a,b --output=OutFile InFile works fine, just as -e a b c -o OutFile InFile does. It seems like the problem arises when the --exclude option is directly before the Required parameter.

[ericnewton76]

Comment by anthonylangsworth
Saturday Oct 22, 2016 at 11:50 GMT

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This appears to be fixed in the master branch, @SuperFXMaster and @nemec . I cannot reproduce the issue. Please let me know if I am incorrect.

[ericnewton76]

Comment by nemec
Saturday Nov 05, 2016 at 07:01 GMT

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I'm still having issues on the master branch with the code snippet I posted above, as well as @SuperFXMaster's.

[ericnewton76]

Comment by hugener
Monday Mar 13, 2017 at 18:21 GMT

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Had quick look into this and could let the example above to run by changing the order of parameters in Concat in the following line:
https://github.com/gsscoder/commandline/blob/master/src/CommandLine/Core/Tokenizer.cs#L54
The changed line becomes:
return tokenizerResult.Map(tokens => values.Concat(tokens));

I'm not sure it's valid for other cases though. Maybe someone who knows more about it can have a look. It would be nice to get a stable version.

[rmunn]

This will be fixed by #684 once it's merged in.