When using an option that has a custom parser with isDefault set to true, the custom parser cannot distinguish between being invoked to provide a default value and being invoked to parse input that has no tokens.
Example:
private static IEnumerable<string> Formats { get; } = new List<string>
{
"foo",
"bar"
};
var option = new Option<List<string>>("--formats",
parseArgument: ParseFormats,
isDefault: true,
description: "Narrows the operation to process only files with these formats. Supported formats: "
+ string.Join(", ", Formats)));
private static List<string> ParseFormats(ArgumentResult result)
{
var formats = result.Tokens.Select(t => t.Value).ToList();
var invalidFormats = formats.Where(t => !Formats.Contains(t));
if (invalidFormats.Any())
{
result.ErrorMessage = $"One or more formats are invalid: {string.Join(", ", invalidFormats)}";
}
//Not provided or no formats specified on the command line
else if (formats.Count == 0)
{
return Formats.ToList();
}
return formats;
}(Formats cannot be an enum here because the list in the actual code is constructed from a list of objects providing a string property)
In this case the parser cannot constrain input to require one or more tokens because this will also be the case when getting a default value.
Some way to know when it's being invoked for a default value would be nice.
When using an option that has a custom parser with
isDefaultset to true, the custom parser cannot distinguish between being invoked to provide a default value and being invoked to parse input that has no tokens.Example:
(Formats cannot be an enum here because the list in the actual code is constructed from a list of objects providing a string property)
In this case the parser cannot constrain input to require one or more tokens because this will also be the case when getting a default value.
Some way to know when it's being invoked for a default value would be nice.