Additional help topic commands now return "subcommand is required" error

[ob-stripe]

#922 changed the behavior of all non-runnable commands, including additional help topic commands.

They now return the new ErrSubCommandRequired error, which by default results in subcommand is required being displayed and exiting with status 1. Both are incorrect for additional help topic commands, whose entire purpose is to display a help message.

Can we restore the previous behavior for additional help topic commands? Naively, something like this:

	if !c.Runnable() {
-		return ErrSubCommandRequired
+		if c.IsAdditionalHelpTopicCommand() {
+			return flag.ErrHelp
+		} else {
+			return ErrSubCommandRequired
+		}
	}

cc @bruceadowns

[bruceadowns]

At first glance, I'm in agreement with refining the change to not consider an additional help topic commands an error.

It would help to see some examples and their expected behavior.

[ob-stripe]

Hi @bruceadowns, thanks and sorry for the delayed reply.

A concrete example would be the resources command in the stripe CLI utility: https://github.com/stripe/stripe-cli/blob/master/pkg/cmd/resources.go

This command doesn't define a Run function or any subcommands (i.e. it's an "additional help topic" command). With cobra 0.0.5, the command behaves as expected:

$ go run cmd/stripe/main.go resources
Available commands:
  3d_secure
  ...
  webhook_endpoints

Use "stripe [command] --help" for more information about a command.

$ echo $?
0

After upgrading to cobra 0.0.6, a subcommand is required error is output and the process exits with status 1 instead:

$ go run cmd/stripe/main.go resources
 Available commands:
  3d_secure
  ...
  webhook_endpoints

Use "stripe [command] --help" for more information about a command.
subcommand is required
exit status 1

$ echo $?
1

Does that make sense? I can provide a minimal self-contained example project if you'd prefer.

If you agree that it makes sense, should I open a PR with the patch I proposed in the first comment, or would you have a more involved solution in mind?

[bruceadowns]

That makes perfect sense, thanks for the clarification. I'd recommend opening a PR, using your proposed solution, with any relatable tests.