git-gem-release-tag

#!/usr/bin/env ruby
# frozen_string_literal: true

# git-gem-release-tag: Create a git tag for a Ruby namespace's version,
#  build a new gem for that tag, and push that gem to Rubygems.

def act(cmd)
  if ARGV.include? "--dry-run"
    puts cmd
  else
    system cmd
  end
end

gemspec_candidates = Dir[File.join(`pwd`.chomp, "*.gemspec")]

abort("No gemspec found.") if gemspec_candidates.empty?
abort("You have more than one gemspec, giving up.") if gemspec_candidates.size > 1

gemspec = gemspec_candidates.first

if Dir.exist?("vendor/bundle")
  act "bundle exec gem build #{gemspec}"
else
  act "gem build #{gemspec}"
end

gemfile_candidates = Dir[File.join(`pwd`.chomp, "*.gem")]

abort("No gemfile found, did `gem build` fail?") if gemfile_candidates.empty?
abort("More than one gemfile found, try running with them removed.") if gemfile_candidates.size > 1

gemfile = File.basename gemfile_candidates.first

/-(?<version>[^-]+)\.gem$/ =~ gemfile

tags = `git tag`.split

abort("Did you forget to bump your version?") if tags.include?(version)

# you'd better hope each of these steps works!
act "git tag #{version}"
act "git push origin #{version}"
act "gem push #{gemfile}"
act "rm -f #{gemfile}"