Hidden commands support

[kfernald]

Our Clikt-based tool has an extensive list of commands, some of which we'd like to "hide" from the help menus as we use them in certain internal scripts but they're not intended to be user-facing. As in: when the parent command shows its help menu, the sub-command doesn't appear in the list of available commands. However the subcommand could still print its own help-menu like normal.

We tried to implement this ourselves by extending CliktHelpFormatter and overriding StringBuilder.addCommands() to hide the commands, but since it's implemented as an extension-function there's not currently a way to have it call the super-class implementation (see https://youtrack.jetbrains.com/issue/KT-11488).

So we'd like to request either adding the feature to hide sub-commands from the parent's list with something like a "hidden" boolean property, or allowing the overriding of the addCommands() method and possibly others by not having them as extension functions.

Figured we'd ask to see if you think this would be a useful feature. If not we can always work around it with some slightly-nasty hacks by overriding the getFormattedHelp() function...

[ajalt]

Great suggestion, we should definitely add that feature.

[kfernald]

Wow thanks for the quick turnaround on it!