parse-gemspec

#!/usr/bin/env ruby

require 'optparse'

gemspecs = Dir["*.gemspec"]

if gemspecs.empty?
    warn "No gemspec found in #{Dir.pwd}"
    exit 10
end

if gemspecs.count > 1
    warn "More than one gemspec found in #{Dir.pwd}"
    exit 10
end

spec = Gem::Specification.load(gemspecs.first)
exit 10 unless spec

def puts!(msg)
  puts msg
  exit
end

OptionParser.new do |opts|
  opts.banner = "Usage: #{File.basename($0)} [options]"
  opts.on("-h", "--help", "Prints this help") do puts! opts end

  opts.on("--name",      "Output name")        do |v| puts! spec.name end
  opts.on("--version",   "Output gem version") do |v| puts! spec.version end
  opts.on("--metadata",  "Output metadata")    do |v| puts! spec.metadata end
  opts.on("--push-host", "Output metadata.allowed_push_host") do |v|
    puts! spec.metadata.dig "allowed_push_host"
  end

  opts.on("--is-pre-release", "Exit 0 if pre-release, 1 otherwise") do |v|
    exit 0 if spec.version.prerelease?
    exit 1
  end
end.parse!