allow delete all on inner join with aliased scope

test plan
 - specs should pass

Change-Id: I37857a560d3159c77706bfc737e71c7ac62c3428
Reviewed-on: https://gerrit.instructure.com/25771
Reviewed-by: Cody Cutrer <cody@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
Product-Review: Rob Orton <rob@instructure.com>
QA-Review: Rob Orton <rob@instructure.com>

config/initializers/active_record.rb

@@ -679,7 +679,7 @@ class ActiveRecord::Base
       join_conditions = []
       joins_sql.strip.split('INNER JOIN')[1..-1].each do |join|
         # this could probably be improved
-        raise "PostgreSQL update_all/delete_all only supports INNER JOIN" unless join.strip =~ /([a-zA-Z'"_]+)\s+ON\s+(.*)/
+        raise "PostgreSQL update_all/delete_all only supports INNER JOIN" unless join.strip =~ /([a-zA-Z'"_]+(?:(?: [aA][sS])? [a-zA-Z_])?)\s+ON\s+(.*)/
         tables << $1
         join_conditions << $2
       end

spec/initializers/active_record_spec.rb

@@ -44,5 +44,17 @@ module ActiveRecord
       end
     end
 
+    describe "deconstruct_joins" do
+      describe "delete_all" do
+        it "should allow delete all on inner join with alias" do
+          User.create(name: 'dr who')
+          User.create(name: 'dr who')
+
+          expect { User.joins("INNER JOIN users u ON users.sortable_name = u.sortable_name").
+            where("u.sortable_name <> users.sortable_name").delete_all }.to_not raise_error
+        end
+      end
+    end
+
   end
 end