For commands implementing Runnable there currently is a CommandLine::run static convenience method that takes care of some boilerplate error handling:

CommandLine.run(new MyApp(), System.err, args);

Unfortunately this static method does not allow us to register subcommands or custom type converters:

• subcommands and type converters need to be registered on a CommandLine instance
• the parsing result is a list of recognized commands. The application logic needs to be given this list to process, which cannot be done via the (parameterless) Runnable::run method.

The purpose of this ticket is to explore possibilities for providing a similar convenience API to applications that have subcommands and custom type converters.