Editing error

[DiaxManPl]

Is there any way to edit this:

I want to make custom "unknown option" text.

[shadowspawn]

There is not direct support for changing the error messages.

You could perhaps override outputError and intercept the message, or if you want additional text after the current message is displayed could catch the matching error and add the text.

https://github.com/tj/commander.js#override-exit-and-output-handling

[DiaxManPl]

Thanks. outputError doesn't work, but custom error handling does.

[DiaxManPl]

Oh. Custom error handling does not replace the message. It just adds custom text to the message.

[shadowspawn]

This is how I thought outputError could be used.

const { program } = require('commander');

program.option('-p, --port <number>');

program.configureOutput({
  outputError: (str, write) => {
    if (str.startsWith('error: unknown option'))
      write('custom unknown option error\n');
    else
      write(str);
  }
});

program.parse();

$ node index.js --port
error: option '-p, --port <number>' argument missing
$ node index.js --surprise
custom unknown option error

[DiaxManPl]

Thanks a lot! It works!

[shadowspawn]

There is an open issue about adding support for modifying and/or localising error messages: #1801