support using a scope as a condition

just like Rails 3

Change-Id: I1a93a63a61ca553676533d303f03f2ee773b0371
Reviewed-on: https://gerrit.instructure.com/25702
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Cody Cutrer <cody@instructure.com>
Product-Review: Cody Cutrer <cody@instructure.com>
QA-Review: Cody Cutrer <cody@instructure.com>

app/controllers/assignments_api_controller.rb

@@ -332,7 +332,7 @@ class AssignmentsApiController < ApplicationController
       if Array(params[:include]).include?('submission')
         submissions = Hash[
           @context.submissions.except(:includes).
-            where(:assignment_id => @assignments).
+            where(:assignment_id => @assignments.except(:order)).
             for_user(@current_user).
             map { |s| [s.assignment_id,s] }
         ]

app/controllers/context_controller.rb

@@ -372,7 +372,7 @@ class ContextController < ApplicationController
       @users.each_with_index{|u, i| @users_hash[u.id] = u; @users_order_hash[u.id] = i }
       @current_user_services = {}
       @current_user.user_services.each{|s| @current_user_services[s.service] = s }
-      @services = UserService.for_user(@users).sort_by{|s| @users_order_hash[s.user_id] || SortLast}
+      @services = UserService.for_user(@users.except(:select, :order)).sort_by{|s| @users_order_hash[s.user_id] || SortLast}
       @services = @services.select{|service|
         !UserService.configured_service?(service.service) || feature_and_service_enabled?(service.service.to_sym)
       }

app/models/assignment.rb

@@ -1226,7 +1226,7 @@ class Assignment < ActiveRecord::Base
         representative
       }.compact
     else
-      visible_students
+      visible_students.to_a
     end
   end
 

app/models/course.rb

@@ -466,10 +466,10 @@ class Course < ActiveRecord::Base
   scope :not_deleted, where("workflow_state<>'deleted'")
 
   scope :with_enrollments, lambda {
-    where("EXISTS (#{Enrollment.active.select("1").where("enrollments.course_id=courses.id").to_sql})")
+    where("EXISTS (?)", Enrollment.active.where("enrollments.course_id=courses.id"))
   }
   scope :without_enrollments, lambda {
-    where("NOT EXISTS (#{Enrollment.active.select("1").where("enrollments.course_id=courses.id").to_sql})")
+    where("NOT EXISTS (?)", Enrollment.active.where("enrollments.course_id=courses.id"))
   }
   scope :completed, lambda {
     joins(:enrollment_term).
@@ -484,12 +484,12 @@ class Course < ActiveRecord::Base
   scope :by_teachers, lambda { |teacher_ids|
     teacher_ids.empty? ?
       none :
-      where("EXISTS (#{Enrollment.active.select("1").where("enrollments.course_id=courses.id AND enrollments.type='TeacherEnrollment' AND enrollments.user_id IN (?)", teacher_ids).to_sql})")
+      where("EXISTS (?)", Enrollment.active.where("enrollments.course_id=courses.id AND enrollments.type='TeacherEnrollment' AND enrollments.user_id IN (?)", teacher_ids))
   }
   scope :by_associated_accounts, lambda{ |account_ids|
     account_ids.empty? ?
       none :
-      where("EXISTS (#{CourseAccountAssociation.select("1").where("course_account_associations.course_id=courses.id AND course_account_associations.account_id IN (?)", account_ids).to_sql})")
+      where("EXISTS (?)", CourseAccountAssociation.where("course_account_associations.course_id=courses.id AND course_account_associations.account_id IN (?)", account_ids))
   }
 
   scope :deleted, where(:workflow_state => 'deleted')

app/models/user.rb

@@ -245,7 +245,7 @@ class User < ActiveRecord::Base
     PageView.for_user(self, options)
   end
 
-  scope :of_account, lambda { |account| where("EXISTS (#{account.user_account_associations.select("1").where("user_account_associations.user_id=users.id").to_sql})") }
+  scope :of_account, lambda { |account| where("EXISTS (?)", account.user_account_associations.where("user_account_associations.user_id=users.id")) }
   scope :recently_logged_in, lambda {
     includes(:pseudonyms).
         where("pseudonyms.current_login_at>?", 1.month.ago).
@@ -261,7 +261,7 @@ class User < ActiveRecord::Base
     end
   }
   scope :name_like, lambda { |name|
-    where("#{wildcard('users.name', 'users.short_name', name)} OR EXISTS (#{Pseudonym.select("1").where(wildcard('pseudonyms.sis_user_id', 'pseudonyms.unique_id', name)).where("pseudonyms.user_id=users.id").active.to_sql})")
+    where("#{wildcard('users.name', 'users.short_name', name)} OR EXISTS (?)", Pseudonym.where(wildcard('pseudonyms.sis_user_id', 'pseudonyms.unique_id', name)).where("pseudonyms.user_id=users.id").active)
   }
   scope :active, where("users.workflow_state<>'deleted'")
 

config/initializers/rails2.rb

@@ -164,6 +164,24 @@ ActiveRecord::Base.class_eval do
       send(callback, *methods)
     end
     alias_method_chain :before_validation, :rails3_compatibility
+
+    def quote_bound_value_with_relations(value)
+      if ActiveRecord::Associations::AssociationCollection === value
+        with_exclusive_scope do
+          value = value.scoped
+        end
+      end
+      if ActiveRecord::NamedScope::Scope === value
+        with_exclusive_scope do
+          unless value.scope(:find, :select)
+            value = value.select("#{value.quoted_table_name}.#{value.primary_key}")
+          end
+          return value.to_sql
+        end
+      end
+      quote_bound_value_without_relations(value)
+    end
+    alias_method_chain :quote_bound_value, :relations
   end
 
   # support 0 arguments
@@ -197,7 +215,14 @@ ActiveRecord::NamedScope::Scope.class_eval do
   # Instead, just take the easy way out and let with_scope do all
   # the hard work
   def unspin
-    with_exclusive_scope { self.scope(:find) }
+    scope = proxy_scope
+    scope = scope.proxy_scope while (ActiveRecord::NamedScope::Scope === scope)
+    scope.send(:with_exclusive_scope) { self.scope(:find) }
+ end
+
+  def is_a?(klass)
+    # no, it's not a freaking Hash, and don't instantiate a gazillion things to find that out
+    super || klass >= Array
   end
 end
 

lib/mutable.rb

@@ -46,7 +46,7 @@ module Mutable
     if self.respond_to? :submissions
       stream_items = StreamItem.select([:id, :context_type, :context_id]).
           where(:asset_type => 'Submission', :asset_id => submissions).
-          includes(:context)
+          includes(:context).to_a
       stream_item_contexts = stream_items.map { |si| [si.context_type, si.context_id] }
       associated_shards = stream_items.inject([]) { |result, si| result | si.associated_shards }
       Shard.with_each_shard(associated_shards) do
@@ -61,7 +61,7 @@ module Mutable
       submissions        = submissions(:include => {:hidden_submission_comments => :author})
       stream_items = StreamItem.select([:id, :context_type, :context_id]).
           where(:asset_type => 'Submission', :asset_id => submissions).
-          includes(:context)
+          includes(:context).to_a
       stream_item_contexts = stream_items.map { |si| [si.context_type, si.context_id] }
       associated_shards = stream_items.inject([]) { |result, si| result | si.associated_shards }
       Shard.with_each_shard(associated_shards) do