class Object

def cucumber_compatible_arity?(args, block)
  return true if block.arity == args.length
  if block.arity < 0
    return true if args.length >= (block.arity.abs - 1)
  end
  false
end

def cucumber_instance_exec(check_arity, pseudo_method, *args, &block)
  cucumber_run_with_backtrace_filtering(pseudo_method) do
    if check_arity && !cucumber_compatible_arity?(args, block)
      instance_exec do
        ari = block.arity
        ari = ari < 0 ? (ari.abs-1).to_s+"+" : ari
        s1 = ari == 1 ? "" : "s"
        s2 = args.length == 1 ? "" : "s"
        raise Cucumber::ArityMismatchError.new(
          "Your block takes #{ari} argument#{s1}, but the Regexp matched #{args.length} argument#{s2}."
        )
      end
    else
      instance_exec(*args, &block)
    end
  end
end

def cucumber_run_with_backtrace_filtering(pseudo_method)
  begin
    yield
  rescue Exception => e
    instance_exec_invocation_line = "#{__FILE__}:#{__LINE__ - 2}:in `cucumber_run_with_backtrace_filtering'"
    replace_instance_exec_invocation_line!((e.backtrace || []), instance_exec_invocation_line, pseudo_method)
    raise e
  end
end

def replace_instance_exec_invocation_line!(backtrace, instance_exec_invocation_line, pseudo_method)
  return if Cucumber.use_full_backtrace
  instance_exec_pos = backtrace.index(instance_exec_invocation_line)
  if instance_exec_pos
    replacement_line = instance_exec_pos + INSTANCE_EXEC_OFFSET
    backtrace[replacement_line].gsub!(/`.*'/, "`#{pseudo_method}'") if pseudo_method
    depth = backtrace.count { |line| line == instance_exec_invocation_line }
    end_pos = depth > 1 ? instance_exec_pos : -1
    backtrace[replacement_line+1..end_pos] = nil
    backtrace.compact!
  else
    # This happens with rails, because they screw up the backtrace
    # before we get here (injecting erb stacktrace and such)
  end
end