Hey there, I'm currently experiencing the following bug:

When using completions, a synchronuous handler does not trigger the validation (which is correct),
but when I have a command foobar <arg> and try to use the completion node . --get-yargs-completions foobar with a custom completion handler that returns a promise

.completion('completion', false as any, (_, argv: Arguments) => {
        return Promise.resolve(['asdf']);
      }),

It does trigger the validation of the required argument and therefor executes the completion handler, but then the process gets exited with the error that a required argument is missing.

Also, when using promises, the handler of the command is executed as well.