Customize help message for a command

[RonWang]

Our goal: customize the help message for the root command.

Existing solution won't help, because we need to append the message on top of auto-gen help, and also modify the auto-gen help a little bit.

Context for our cmd app: below is the root cmd, and we have a sub-cmd under the root as well as a git-style-sub-command.

commander
    .description('')
    .command('sub-cmd')
    .command('git-style-sub-cmd')
    .version(require('../package.json').version)
    .option('-h, --help', 'output help message', () => {
        console.log('custom help msg');
    })
    .parse(process.argv);

In the example I tried using option('-h, --help'), the console.log works for me with my demanded help output. But when I try sub-cmd and git-style-sub-cmd, the help message for the root command is always coming along when I type "cmd sub-cmd --help" and "cmd git-style-sub-cmd --help".

I noticed #242 , where @shadowspawn mentioned it won't be supported. Reopen it as it'd be an important feature for us.

[RonWang]

lol great post! #1111111111(2)

[shadowspawn]

I'll try and explain what is happening with what you tried.

    .option('-h, --help', 'output help message', () => {
        console.log('custom help msg');
    })

This adds an option which effectively overrides the built-in help since it uses the same flags. The callback is used for "Custom option processing" and covered in the README.

Flags are treated as "global" and these three calls get processed much the same way and call your action handler:

my-command --help
my-command --help sub-cmd
my-command sub-cmd --help

This approach would let you customise the help for your main command, but you do miss out on the built-in support for help on the subcommands.

[shadowspawn]

Related issue, prefix help with some text: #578

[shadowspawn]

Currently there is a single event which is emitted after the help is displayed, --help.

A possible approach for allowing more control might be to emit three events:

• help:header
• help:body
• help:footer

If there is a listener for help:body then it is called instead of the normal help.

[shadowspawn]

This issue has not had any activity in over six months. It isn't likely to get acted on due to this report.

I quite like the help:header, help:body, help:footer idea, and will be keeping an eye on new issues to see if it would be useful.

Feel free to open a new issue if it comes up again, with new information and renewed interest.

Thank you for your contributions.

[DiaxManPl]

Can anyone give me example usage of help:body?

[shadowspawn]

The help:body pattern did not get implemented. The features that did get added were .addHelpText() and .configureHelp(), and a Help class for more complex overrides.

[DiaxManPl]

Ok. Sorry.