config/initializers/redis.rb

redis.rb

# Mock Redis
class MockRedis
  attr_accessor :store

  def initialize
    @store = {}
  end

  def flushall
    @store = {}
  end

  def incrby(key, increment)
    @store[key] ||= 0
    @store[key] += increment
  end

  def incr(key)
    incrby(key, 1)
  end

  def hincrby(key, field, increment)
    @store[key] ||= {}
    @store[key][field] ||= 0
    @store[key][field] += increment
  end

  def hvals(key)
    @store[key] ||= {}
    @store[key].values.map(&:to_s)
  end

  def hdel(key, *fields)
    return 0 if @store[key].nil?
    i = 0
    fields.each { |field|
      tmp = @store[key].delete(field)
      i += 1 unless tmp.nil?
    }
    i
  end

  def hget(key, field)
    @store[key] ||= {}
    @store[key][field].try(:to_s)
  end

  def get(key)
    @store[key].try(:to_s)
  end

  def expire(key, ttl)
  end
end

if Rails.env.test?
  $redis = MockRedis.new
else
  redis = Redis.new(:host => 'localhost', :port => 6379, :thread_safe => true)
  $redis = Redis::Namespace.new(Rails.env.to_s, :redis => redis)
end