class ActiveSupport::Logger

def self.logger_outputs_to?(logger, *sources)

# => true
ActiveSupport::Logger.logger_outputs_to?(logger, '/var/log/rails.log')
logger = Logger.new('/var/log/rails.log')

# => true
ActiveSupport::Logger.logger_outputs_to?(logger, STDOUT)
logger = Logger.new(STDOUT)

Returns true if the logger destination matches one of the sources 
def self.logger_outputs_to?(logger, *sources)
  loggers = if logger.is_a?(BroadcastLogger)
    logger.broadcasts
  else
    [logger]
  end
  logdevs = loggers.map { |logger| logger.instance_variable_get(:@logdev) }
  logger_sources = logdevs.filter_map { |logdev| logdev.try(:filename) || logdev.try(:dev) }
  normalize_sources(sources).intersect?(normalize_sources(logger_sources))
end