Memoization instance variables should not be set to nil but removed!

Author: stevegeek

lib/encoded_id/rails/model.rb

@@ -39,8 +39,8 @@ def name_for_encoded_id_slug
       # When duplicating an ActiveRecord object, we want to reset the memoized encoded_id
       def dup
         super.tap do |new_record|
-          new_record.instance_variable_set(:@encoded_id, nil)
-          new_record.instance_variable_set(:@slugged_encoded_id, nil)
+          new_record.send(:remove_instance_variable, :@encoded_id) if new_record.instance_variable_defined?(:@encoded_id)
+          new_record.send(:remove_instance_variable, :@slugged_encoded_id)  if new_record.instance_variable_defined?(:@slugged_encoded_id)
         end
       end
     end

test/encoded_id/test_rails.rb

@@ -162,4 +162,23 @@ def test_duplicated_record_has_different_encoded_id
   def test_duplicated_record_has_different_slugged_encoded_id
     refute_equal model.slugged_encoded_id, model.dup.slugged_encoded_id
   end
+
+  def test_both_encoded_id_and_slugged_id_are_recalculated_on_duplication
+    initial_encoded_id = model.encoded_id
+    initial_slugged_encoded_id = model.slugged_encoded_id
+    new_model = model.dup
+    refute_equal initial_encoded_id, new_model.encoded_id
+    refute_equal initial_slugged_encoded_id, new_model.slugged_encoded_id
+  end
+
+  def test_both_encoded_id_and_slugged_id_are_recalculated_on_duplication_and_persisted
+    initial_encoded_id = model.encoded_id
+    initial_slugged_encoded_id = model.slugged_encoded_id
+    new_model = model.dup
+    new_model.save
+    refute_equal initial_encoded_id, new_model.encoded_id
+    refute_equal initial_slugged_encoded_id, new_model.slugged_encoded_id
+    refute_nil new_model.encoded_id
+    refute_nil new_model.slugged_encoded_id
+  end
 end