Print a prettier stack trace for Ruby exceptions

pretty-exception.rb

def colorize(text, color_code)
  "\e[#{color_code}m#{text}\e[0m"
end

begin
  # Here be dangerous things.
rescue => e
  print "\r" << (' ' * 50) << "\n"
  stacktrace = e.backtrace.map do |call|
    if parts = call.match(/^(?<file>.+):(?<line>\d+):in `(?<code>.*)'$/)
      file = parts[:file].sub /^#{Regexp.escape(File.join(Dir.getwd, ''))}/, ''
      line = "#{colorize(file, 36)} #{colorize('(', 37)}#{colorize(parts[:line], 32)}#{colorize('): ', 37)} #{colorize(parts[:code], 31)}"
    else
      line = colorize(call, 31)
    end
    line
  end
  puts "Fatal error:\n"
  stacktrace.each { |line| puts line }

  raise "Failed"
end