Git tag version bumper

version.rb

module Release
  @tags =  %x[ git tag --sort version:refname ].split("\n")
  @current_tag = @tags.last
  @current_version = @current_tag.gsub("v","")
  @major, @minor, @patch = @current_version.split(".").map(&:to_i)

  def self.tags
    @tags
  end

  def self.current_tag
    @current_tag
  end

  def self.bump_version release_type, metadata
    case release_type
    when "major"
      @major += 1
      @minor = @patch = 0
    when "minor"
      @minor += 1
      @patch = 0
    when "patch"
      @patch += 1
    else # Default case
      @patch += 1
    end

    bumped_version = "v#{@major}.#{@minor}.#{@patch}"

    (metadata.present?)? bumped_version + "-#{metadata}" : bumped_version
  end

  def self.next_tag release_type="patch",metadata=nil
    self.bump_version(release_type,metadata)
  end
end