Scopes cached in production mode

ticket #4708 Query cache broken when using associations with scopes has same issue. I fixed that issue by not caching the arguments. That patch never got picked up. However Pratik did patch the code by caching the arguments.

I am working on a patch for this ticket.

@Caleb in script/console in production mode I am getting new value every single time.

class User < ActiveRecord::Base
  scope :recent, lambda { where("created_at <= ?", Time.now) }
end

ruby-1.8.7-p249 > User.recent
  User Load (0.3ms)  SELECT "users".* FROM "users" WHERE (created_at <= '2010-06-24 21:55:06.057378')
 => [] 
ruby-1.8.7-p249 > User.recent
  User Load (0.3ms)  SELECT "users".* FROM "users" WHERE (created_at <= '2010-06-24 21:55:07.225097')
 => [] 
ruby-1.8.7-p249 > User.recent
  User Load (0.2ms)  SELECT "users".* FROM "users" WHERE (created_at <= '2010-06-24 21:55:07.792841')
 => []

Yes, in console mode you get the correct values. However, if you put the code in your controller and use a web server, you do not.

Here is my code for rail3 app.

class User < ActiveRecord::Base
  scope :recent, lambda { where("created_at <= ?", Time.now) }
end

def index
   User.recent.all.inspect
   User.recent.all.inspect
   render :text => 'done'
end

I changed the log settings for production mode to see sql statement.
I started server in production mode. This is the sql statements I got.

User Load (0.2ms)  SELECT "users".* FROM "users" WHERE (created_at <= '2010-06-25 01:15:31.495205')
User Load (0.2ms)  SELECT "users".* FROM "users" WHERE (created_at <= '2010-06-25 01:15:31.510747')

When I refresh the page I get this sql

User Load (0.2ms)  SELECT "users".* FROM "users" WHERE (created_at <= '2010-06-25 01:15:39.042884')
User Load (0.2ms)  SELECT "users".* FROM "users" WHERE (created_at <= '2010-06-25 01:15:39.044806')

Could it be possible that some other gem/plugin is interfering with the behavior.

I must apologize; the code snippet I posted wasn't the line not working properly. I have found the source of the issue, after disabling all Gems/plugins. The problem is in chaining scopes.

In the following code, Auction.active returns new results depending on the time:

class Auction < ActiveRecord::Base
  scope :started, lambda { where("starting_at <= ?", Time.now) }
  scope :unfinished, lambda { where("ending_at > ?", Time.now) }
  scope :active, lambda {where("ending_at > ?", Time.now).where("starting_at <= ?", Time.now) }
end

However, in this code the result of Auction.active is the same from server start:

class Auction < ActiveRecord::Base
  scope :started, lambda { where("starting_at <= ?", Time.now) }
  scope :unfinished, lambda { where("ending_at > ?", Time.now) }
  scope :active, started.unfinished
end

I did not even know what one could do something like that -- define a scope which in turn depends on other scope.