rails--rails/activesupport/lib/active_support/clean_logger.rb

require 'logger'

class Logger #:nodoc:
  # Silences the logger for the duration of the block.
  def silence(temporary_level = Logger::ERROR)
    old_logger_level, self.level = level, temporary_level
    yield self
  ensure
    self.level = old_logger_level
  end

  private
    # Ruby 1.8.3 transposed the msg and progname arguments to format_message.
    # We can't test RUBY_VERSION because some distributions don't keep Ruby
    # and its standard library in sync, leading to installations of Ruby 1.8.2
    # with Logger from 1.8.3 and vice versa.
    if method_defined?(:formatter=)
      def format_message(severity, timestamp, progname, msg)
        "#{msg}\n"
      end
    else
      def format_message(severity, timestamp, msg, progname)
        "#{msg}\n"
      end
    end
end