gistfile1.rb

# Version 2 -- the cool version
require 'redis'
require 'forwardable' #standard ruby library
class RedisTester
  # this way, we create the instance and check to see it's running every time
  # we ask for it automatically.
  def redis
    @redis ||= Redis.new
    raise unless redis_is_running?
    @redis
  end
  
  delegate [:set, :get] => :redis
  
  def redis_is_running?
    @redis.ping == 'PONG'
  rescue Redis::CannotConnectError
    return false
  end 
end

redistester.rb

require 'redis'

# Version 1
class RedisTester
  
  # this way, we create the instance and check to see it's running every time
  # we ask for it automatically.
  def redis
    @redis ||= Redis.new
    raise unless redis_is_running?
    @redis
  end
  
  def set(key, value)
    redis.set key, value
  end

  def get(key)
    @redis.get key
  end
  
  def redis_is_running?
    #no need to explicitly return true, that'll happen here. This
    # method can either fail or return PONG
    @redis.ping == 'PONG'
  #ruby has a special syntax for catching an error in a method like this.
  # it's just shorthand.
  rescue Redis::CannotConnectError
    return false
  end 
end