Nulling a property of CommandLineArgumentsConfiguration between assigning it to CommandLineArguments.Configuration and calling CommandLineArguments.TryParse() or .DisplayHelp() results in NullReferenceExceptions

[akamsteeg]

It's possible to create a CommandLineArgumentsConfiguration object, assign it to CommandLineArguments.Configuration and then null the Parser and/or HelpWriter property of the configuration. This results in NullRefefenceExceptions when calling CommandLineArguments.TryParse() or CommandLineArguments.DisplayHelp() because the configuration is only validated when assiging it to CommandLineArguments.Configuration.

Example

var config = new CommandLineArgumentsConfiguration()
{
  Parser = new WindowsStyleParser(),
  HelpWriter = new WindowsStyleHelpWriter()
};

CommandLineArguments.Configuration = config; // Configuration is validated here

config.Parser = null;

CommandLineArguments.TryParse(args, out var parsedArguments);; // NullReferenceException