Get caller's caller for Ruby exception

Question

Right now our application is running on Heroku, and in order to save restarts and possible latency the application is designed to cache all errors and send them to stderr and just server a stale cache until the issue is resolved by another push. This prevents application takedown...

However, the logs keep filling up excessively with entire traces which we don't want, so I built a little snippet (that is partially stolen from Rails) to parse caller and only send that line, however with errors being sent from a rescue, we get the wrong line so I was wondering how I could get the caller or the caller or if there was a better way to handle this situation. Here is the snippet:

module StdErr
  def error(message)
    file = 'Unknown'
    line = '0'

    if /^(.+?):(\d+)(?::in `(.*)')?/ =~ caller[1]
      file = $1
      line = $2
    end

    $stderr.puts "ERROR: #{message} on line #{line} of #{file}"
  end
end

Answer 1

If I get it, you want to raise a exception with a backtrace that begins on the caller of the caller. Do it:

def raise_cc(*args)
  raise(*args)
rescue Exception
  # Raises the same exception, removing the last 2 items
  # from backtrace (this method and its caller). The first
  # will be the caller of the caller of this method.
  raise($!.class, $!.message, $!.backtrace[2..(-1)])
end

Answer 2

caller returns an array and you can go deeper into the call stack by looking at it's later elements (note that you're looking at caller[1])