Rails 4 compatibility

* also bumps the activerecord dependency requirement to be 3.0 or higher as delayed_job 3.x does not support activerecord 2.x
* because of the activerecord 3.0+ requirement change, the scoping done in backend/active_record.rb can be updated to use Rails 3 query methods
* also removes a spec that tested `attr_accessible` which is no longer part of Rails 4

delayed_job_active_record.gemspec

@@ -1,7 +1,7 @@
 # coding: utf-8
 
 Gem::Specification.new do |spec|
-  spec.add_dependency   'activerecord', ['>= 2.1.0', '< 4']
+  spec.add_dependency   'activerecord', ['>= 3.0', '< 4.1']
   spec.add_dependency   'delayed_job', '~> 3.0'
   spec.authors        = ["Brian Ryckbost", "Matt Griffin", "Erik Michaels-Ober"]
   spec.description    = 'ActiveRecord backend for Delayed::Job, originally authored by Tobias Lütke'

lib/delayed/backend/active_record.rb

@@ -7,8 +7,7 @@ module ActiveRecord
       class Job < ::ActiveRecord::Base
         include Delayed::Backend::Base
 
-        attr_accessible :priority, :run_at, :queue, :payload_object,
-          :failed_at, :locked_at, :locked_by
+        scope :by_priority, lambda { order('priority ASC, run_at ASC') }
 
         before_save :set_default_run_at
 
@@ -23,10 +22,6 @@ def self.ready_to_run(worker_name, max_run_time)
           where('(run_at <= ? AND (locked_at IS NULL OR locked_at < ?) OR locked_by = ?) AND failed_at IS NULL', db_time_now, db_time_now - max_run_time, worker_name)
         end
 
-        def self.by_priority
-          order('priority ASC, run_at ASC')
-        end
-
         def self.before_fork
           ::ActiveRecord::Base.clear_all_connections!
         end
@@ -37,22 +32,21 @@ def self.after_fork
 
         # When a worker is exiting, make sure we don't have any locked jobs.
         def self.clear_locks!(worker_name)
-          update_all("locked_by = null, locked_at = null", ["locked_by = ?", worker_name])
+          where(:locked_by => worker_name).update_all(:locked_by => nil, :locked_at => nil)
         end
 
         def self.reserve(worker, max_run_time = Worker.max_run_time)
           # scope to filter to records that are "ready to run"
           readyScope = self.ready_to_run(worker.name, max_run_time)
 
           # scope to filter to the single next eligible job
-          nextScope = readyScope.scoped
-          nextScope = nextScope.scoped(:conditions => ['priority >= ?', Worker.min_priority]) if Worker.min_priority
-          nextScope = nextScope.scoped(:conditions => ['priority <= ?', Worker.max_priority]) if Worker.max_priority
-          nextScope = nextScope.scoped(:conditions => ["queue IN (?)", Worker.queues]) if Worker.queues.any?
-          nextScope = nextScope.scoped.by_priority.limit(1)
+          readyScope = readyScope.where('priority >= ?', Worker.min_priority) if Worker.min_priority
+          readyScope = readyScope.where('priority <= ?', Worker.max_priority) if Worker.max_priority
+          readyScope = readyScope.where(:queue => Worker.queues) if Worker.queues.any?
+          job = readyScope.by_priority.first
 
           now = self.db_time_now
-          job = nextScope.first
+
           return unless job
           job.with_lock do
             job.locked_at = now

spec/delayed/backend/active_record_spec.rb

@@ -43,21 +43,6 @@
     end
   end
 
-  context "ActiveRecord::Base.send(:attr_accessible, nil)" do
-    before do
-      Delayed::Backend::ActiveRecord::Job.send(:attr_accessible, nil)
-    end
-
-    after do
-      Delayed::Backend::ActiveRecord::Job.send(:attr_accessible, *Delayed::Backend::ActiveRecord::Job.new.attributes.keys)
-    end
-
-    it "is still accessible" do
-      job = Delayed::Backend::ActiveRecord::Job.enqueue :payload_object => EnqueueJobMod.new
-      expect(Delayed::Backend::ActiveRecord::Job.find(job.id).handler).to_not be_blank
-    end
-  end
-
   context "ActiveRecord::Base.table_name_prefix" do
     it "when prefix is not set, use 'delayed_jobs' as table name" do
       ::ActiveRecord::Base.table_name_prefix = nil

spec/spec_helper.rb

@@ -44,7 +44,7 @@ class Story < ActiveRecord::Base
   self.primary_key = :story_id
   def tell; text; end
   def whatever(n, _); tell*n; end
-  default_scope where(:scoped => true)
+  default_scope { where(:scoped => true) }
 
   handle_asynchronously :whatever
 end