lib/left_joins.rb in left_joins-1.0.0 vs lib/left_joins.rb in left_joins-1.0.1

@@ -2,11 +2,11 @@
 require 'active_record'
 require 'active_record/relation'
 
 module ActiveRecord::QueryMethods
   IS_RAILS3_FLAG = Gem::Version.new(ActiveRecord::VERSION::STRING) < Gem::Version.new('4.0.0')
-  if not method_defined?(:check_if_method_has_arguments!)
+  if IS_RAILS3_FLAG
     def check_if_method_has_arguments!(method_name, args)
       if args.blank?
         raise ArgumentError, "The method .#{method_name}() must contain arguments."
       end
     end
@@ -64,9 +64,31 @@
       else
         alias_method :make_constraints_without_hooking_join_type, :make_constraints
         def make_constraints(*args, join_type)
           join_type = Thread.current.thread_variable_get :left_joins_join_type || join_type
           return make_constraints_without_hooking_join_type(*args, join_type)
+        end
+      end
+    end
+
+    module ActiveRecord::Calculations
+      def perform_calculation(operation, column_name, options = {})
+        operation = operation.to_s.downcase
+
+        # If #count is used with #distinct (i.e. `relation.distinct.count`) it is
+        # considered distinct.
+        distinct = IS_RAILS3_FLAG ? options[:distinct] || self.uniq_value : self.distinct_value
+
+        if operation == "count"
+          column_name ||= select_for_count
+          column_name = primary_key if column_name == :all && distinct
+          distinct = nil if column_name =~ /\s*DISTINCT[\s(]+/i
+        end
+
+        if group_values.any?
+          execute_grouped_calculation(operation, column_name, distinct)
+        else
+          execute_simple_calculation(operation, column_name, distinct)
         end
       end
     end
   end
 end