Bug #14728: OptionParser takes other options as argument values

• Status: Rejected
• Priority: Normal
• Assignee: -
• Target version: -
• ruby -v: ruby 2.0.0p648 (2015-12-16 revision 53162) [universal.x86_64-darwin16]
• Backport: 2.3: UNKNOWN, 2.4: UNKNOWN, 2.5: UNKNOWN

test.rb

require 'optparse'

options = {}
OptionParser.new do |opts|
  opts.banner = "Usage: test.rb [options]"

  opts.on("--verbose", "Run verbosely") do |v|
    options[:verbose] = v
  end
  opts.on("--custom MANDATORY", "custom") do |x|
    options[:custom] = x
  end
end.parse!

p options

If I run the above script as follows below is output:

$ ruby test.rb --custom --verbose
{:custom=>"--verbose"}

This is not the expected behaviour as --verbose should not be set as the option value.

• Description updated (diff)

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Rejected
• Description updated (diff)

If --custom with no argument is allowed, it is not "MANDATORY".

Try:

  opts.on("-q","--custom [CUSTOM]", "custom") do |x|
    options[:custom] = x
  end

nobu (Nobuyoshi Nakada) wrote:

If --custom with no argument is allowed, it is not "MANDATORY".

Try:

  opts.on("-q","--custom [CUSTOM]", "custom") do |x|
    options[:custom] = x
  end

--custom with no argument is not allowed, hence an error would be ideal in the above scenario.

[nobu (Nobuyoshi Nakada)]

In common, an argument is determined by the preceding option, consider grep command's -e option.
If you want to disallow an argument starting with -, you'd need to specify a pattern

  opts.on("-q","--custom MANDATORY", "custom", /\A(?!-)/) do |x|
    options[:custom] = x
  end

or allowed values

  opts.on("-q","--custom MANDATORY", "custom", %w[A B C]) do |x|
    options[:custom] = x
  end

nobu (Nobuyoshi Nakada) wrote:

In common, an argument is determined by the preceding option, consider grep command's -e option.
If you want to disallow an argument starting with -, you'd need to specify a pattern

  opts.on("-q","--custom MANDATORY", "custom", /\A(?!-)/) do |x|
    options[:custom] = x
  end

or allowed values

  opts.on("-q","--custom MANDATORY", "custom", %w[A B C]) do |x|
    options[:custom] = x
  end

Thanks!