Subcommand generate-schema with no arguments and with --help arguments throws

[aj-stein-nist]

Describe the bug

When using ad-hoc CLI testing to compare and contrast with the XSLT implementation today with @nikitawootten-nist, we determined there are consistency issues with the generate-schema subcommand of CLI as of commit 47a9687. It appears I had detected the issue given the current tests by "passing" the invocation of metaschema-cli generate-schema --help as returning ExitCode.INVALID_COMMAND, but did not realize this behavior is also exhibited running it metaschema-cli generate-schema , albeit it with different diagnostic messages for the similar commands. An updated repro branch for this bug report can be found via the URL below.

Who is the bug affecting?

Users of the metaschema-cli directly and/or using the nested oscal-cli metaschema ... subcommands.

What is affected by this bug?

Stability of using the help menu or running the subcommands without argument for installation tests interactively or scripting.

When does this occur?

Consistently.

How do we replicate the issue?

1. Clone the repo and checkout the repro branch from the fork.
2. Run mvn test on the CLI or via the command line.

Expected behavior (i.e. solution)

The CLI successful returns with ExitCode.OK and returns the help menu, it does not give error messaging about parameters arguments that would not be supplied when arguments are not provided, only the error message is displayed.

Other Comments

N/A

[aj-stein-nist]

After reviewing test failures and reviewing gov.nist.secauto.metaschema.cli.processor.CLIProcessor.toOptions() and process command, I am going to likely need to implement Apache Commons CLI OptionGroups under the hood to resolve this issue.

Research: https://stackoverflow.com/a/36722157