Move Relation#spawn and Relation#merge to a separate module

activerecord/lib/active_record.rb

@@ -55,6 +55,7 @@ module ActiveRecord
       autoload :FinderMethods
       autoload :CalculationMethods
       autoload :PredicateBuilder
+      autoload :SpawnMethods
     end
 
     autoload :Base

activerecord/lib/active_record/relation.rb

 module ActiveRecord
   class Relation
-    include QueryMethods, FinderMethods, CalculationMethods
+    include QueryMethods, FinderMethods, CalculationMethods, SpawnMethods
 
     delegate :length, :collect, :map, :each, :all?, :to => :to_a
 
@@ -28,41 +28,6 @@ def create!(*args, &block)
       with_create_scope { @klass.create!(*args, &block) }
     end
 
-    def merge(r)
-      raise ArgumentError, "Cannot merge a #{r.klass.name} relation with #{@klass.name} relation" if r.klass != @klass
-
-      merged_relation = spawn(table).eager_load(r.eager_load_associations).preload(r.preload_associations).includes(r.include_associations)
-      merged_relation.readonly = r.readonly
-
-      [self.relation, r.relation].each do |arel|
-        merged_relation = merged_relation.
-          joins(arel.joins(arel)).
-          group(arel.groupings).
-          limit(arel.taken).
-          offset(arel.skipped).
-          select(arel.send(:select_clauses)).
-          from(arel.sources)
-      end
-
-      relation_order = r.send(:order_clause)
-      merged_order = relation_order.present? ? relation_order : order_clause
-      merged_relation = merged_relation.order(merged_order)
-
-      merged_wheres = @relation.wheres
-
-      r.wheres.each do |w|
-        if w.is_a?(Arel::Predicates::Equality)
-          merged_wheres = merged_wheres.reject {|p| p.is_a?(Arel::Predicates::Equality) && p.operand1.name == w.operand1.name }
-        end
-
-        merged_wheres << w
-      end
-
-      merged_relation.where(*merged_wheres)
-    end
-
-    alias :& :merge
-
     def respond_to?(method, include_private = false)
       return true if @relation.respond_to?(method, include_private) || Array.method_defined?(method)
 
@@ -164,16 +129,6 @@ def reset
       self
     end
 
-    def spawn(relation = @relation)
-      relation = Relation.new(@klass, relation)
-      relation.readonly = @readonly
-      relation.preload_associations = @preload_associations
-      relation.eager_load_associations = @eager_load_associations
-      relation.include_associations = @include_associations
-      relation.table = table
-      relation
-    end
-
     def table
       @table ||= Arel::Table.new(@klass.table_name, Arel::Sql::Engine.new(@klass))
     end

activerecord/lib/active_record/relation/spawn_methods.rb

+module ActiveRecord
+  module SpawnMethods
+    def spawn(relation = @relation)
+      relation = Relation.new(@klass, relation)
+      relation.readonly = @readonly
+      relation.preload_associations = @preload_associations
+      relation.eager_load_associations = @eager_load_associations
+      relation.include_associations = @include_associations
+      relation.table = table
+      relation
+    end
+
+    def merge(r)
+      raise ArgumentError, "Cannot merge a #{r.klass.name} relation with #{@klass.name} relation" if r.klass != @klass
+
+      merged_relation = spawn(table).eager_load(r.eager_load_associations).preload(r.preload_associations).includes(r.include_associations)
+      merged_relation.readonly = r.readonly
+
+      [self.relation, r.relation].each do |arel|
+        merged_relation = merged_relation.
+          joins(arel.joins(arel)).
+          group(arel.groupings).
+          limit(arel.taken).
+          offset(arel.skipped).
+          select(arel.send(:select_clauses)).
+          from(arel.sources)
+      end
+
+      relation_order = r.send(:order_clause)
+      merged_order = relation_order.present? ? relation_order : order_clause
+      merged_relation = merged_relation.order(merged_order)
+
+      merged_wheres = @relation.wheres
+
+      r.wheres.each do |w|
+        if w.is_a?(Arel::Predicates::Equality)
+          merged_wheres = merged_wheres.reject {|p| p.is_a?(Arel::Predicates::Equality) && p.operand1.name == w.operand1.name }
+        end
+
+        merged_wheres << w
+      end
+
+      merged_relation.where(*merged_wheres)
+    end
+
+    alias :& :merge
+
+  end
+end