Weird relationship behavior on Rails 3 and update_attribute - ruby-on-rails

Question

I'm having a hard time trying to find out why a test is failing:
describe User, "Instance Methods" do
describe "leave_group!" do
it "should set group_id to nil" do
#user = Factory(:user)
#group_2 = Factory(:group, :owner => #user)
#user.leave_group!
#user.reload.group_id.should be_nil # THIS LINE IS FAILING!!!
end
it "should assign another owner to group, if owner was user" do
#user = Factory(:user)
#group = Factory(:group, :owner => #user)
1.upto(4) { #group.add_user Factory(:user) }
#user.leave_group!
#group.reload.owner.should_not eql(#user)
end
end
end
These are the models I'm using:
class User < ActiveRecord::Base
# Associations
has_one :own_group, :class_name => "Group", :foreign_key => "owner_id"
belongs_to :group
def leave_group!
current_group_id, current_group_owner = self.group.id, self.group.owner
self.group_id = nil
save!
Group.find(current_group_id).randomize_owner! if current_group_owner == self
end
end
class Group < ActiveRecord::Base
# Associations
has_many :users
belongs_to :owner, class_name: "User"
def randomize_owner!
current_users = self.users
return false unless current_users.length > 1
begin
new_user = current_users.sort_by { rand }.first
end while self.owner == new_user
self.owner_id = new_user.id
save!
end
end
Am I doing something wrong here? Could I improve it? And more importantly, why is that single test failing?
Here's the log output for runing that single test:
SQL (0.2ms) SELECT name
FROM sqlite_master
WHERE type = 'table' AND NOT name = 'sqlite_sequence'
AREL (0.3ms) INSERT INTO "users" ("name", "uid", "provider", "email", "image_url", "group_id", "created_at", "updated_at", "timezone", "public_readings", "is_visible_on_leaderboards", "phone_number") VALUES ('John Doe', '314159265', 'facebook', 'john#does.com', NULL, NULL, '2011-07-18 02:02:08.455229', '2011-07-18 02:02:08.455229', NULL, 't', 't', NULL)
Group Load (0.1ms) SELECT "groups".* FROM "groups" WHERE "groups"."key" = 'SNYEMJ' LIMIT 1
AREL (0.1ms) INSERT INTO "groups" ("name", "key", "score", "owner_id", "created_at", "updated_at") VALUES ('John''s Group', 'SNYEMJ', 0, 1, '2011-07-18 02:02:08.522442', '2011-07-18 02:02:08.522442')
AREL (0.0ms) UPDATE "users" SET "group_id" = 1, "updated_at" = '2011-07-18 02:02:08.524342' WHERE "users"."id" = 1
Group Load (0.1ms) SELECT "groups".* FROM "groups" WHERE "groups"."id" = 1 LIMIT 1
User Load (0.2ms) SELECT "users".* FROM "users" WHERE ("users".group_id = 1)
User Load (0.2ms) SELECT "users".* FROM "users" WHERE "users"."id" = 1 LIMIT 1
The last 3 lines are all selects, notice rails doesn't even try to remove the group_id from the user. (There are 2 inserts, 1 for the test user and 1 for the test group and 1 update which assigns group_id to the test user).

Answer 1

Try adding a #user.reload call before #user.leave_group in the test.
Even though the user record is updated with it's group in the DB when you create #group_2 from the factory, I suspect the #user object is not. Then you call leave_group! with a #user with a group ID of nil, so the save won't do anything because the object is unchanged. Then in the next line of your test you reload the #user, which now has the group_id from the DB assigned earlier.

Answer 2

try to chance the model class as following:
class User < ActiveRecord::Base
# Associations
has_one :own_group, :class_name => "Group", :foreign_key => "owner_id"
belongs_to :group
def leave_group!
group_randomize_owner
self.group.clear
end
private
def group_randomize_owner
if group.owner == self
group.randomize_owner!
end
end
end