function foo --description "Example argparse usage"
  set --local options 'h/help' 'n/count=!_validate_int --min 1'

  argparse $options -- $argv

  if set --query _flag_help
    printf "Usage: foo [OPTIONS]\n\n"
    printf "Options:\n"
    printf "  -h/--help       Prints help and exits\n"
    printf "  -n/--count=NUM  Count (minimum 1, default 10)"
    return 0
  end

  set --query _flag_count; or set --local _flag_count 10

  for i in (seq $_flag_count); echo foo; end
end

If you’re using fish shell on macOS and want to use nvm, here are the steps I took to accomplish it using brew and bass. The above message is returned after brew installs nvm. Brew install also…