Bug #18783: OptionParser should recognize "-" as an optional argument

• Status: Open
• Priority: Normal
• Assignee: -
• Target version: -
• ruby -v: ruby 2.7.4p191, ruby 3.1.2p20
• Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN

[konsolebox (K B)]

require 'optparse'

optarg = nil

OptionParser.new do |parser|
  parser.on("-o", "--opt [ARG]", "Option with optional argument") do |arg|
    optarg = arg
  end
end.parse!

puts "#{optarg.inspect}, #{ARGV.inspect}"

Executing the code above with -o - as arguments outputs nil, ["-"] when it should produce "-", [] instead.

OptionParser recognizes - as a general non-option argument but it doesn't do the same when - follows an option with an optional argument.

In my shell script, I consider options as -?* (glob) instead of -* so - is also considered as a valid argument. Perhaps OptionParser should do the same.

[konsolebox (K B)]

Any thoughts on this?

I created a PR: https://github.com/ruby/ruby/pull/5918