Support Rails normalizes method and fix empty string handling consistency

lib/enumerize/activerecord.rb

@@ -115,10 +115,19 @@ def initialize(attr, subtype)
       end
 
       def serialize(value)
-        v = @attr.find_value(value)
-        return value unless v
+        # First try to find the enumerize value directly
+        enumerize_value = @attr.find_value(value)
+
+        # If not found and we have a subtype, delegate to it for transformation
+        # (e.g., normalization) and try again
+        if !enumerize_value && @subtype
+          casted_value = @subtype.cast(value)
+          enumerize_value = @attr.find_value(casted_value)
+        end
 
-        v.value
+        return value unless enumerize_value
+
+        enumerize_value.value
       end
 
       def cast(value)
@@ -127,10 +136,15 @@ def cast(value)
 
         # First try to find the enumerize value directly
         enumerize_value = @attr.find_value(value)
-        return enumerize_value if enumerize_value
 
-        # If not found, delegate to subtype then try to find value
-        @attr.find_value(@subtype.cast(value))
+        # If not found and we have a subtype, delegate to it for transformation
+        # (e.g., normalization) and try again
+        if !enumerize_value && @subtype
+          casted_value = @subtype.cast(value)
+          enumerize_value = @attr.find_value(casted_value)
+        end
+
+        enumerize_value
       end
 
       def as_json(options = nil)

lib/enumerize/attribute.rb

@@ -88,6 +88,15 @@ def respond_to_missing?(method, include_private=false)
       @value_hash.include?(method.to_s) || super
     end
 
+    # Defines getter and setter methods for the enumerated attribute.
+    #
+    # The setter method behavior:
+    # - Valid enum values: Stores the underlying value
+    # - Empty strings: Converts to nil (historically consistent behavior, now explicitly maintained)
+    # - Invalid values: Passes through to allow Rails processing (e.g., normalizes, type casting)
+    #
+    # Note: Empty string to nil conversion was implicit in previous versions but is now
+    # explicitly implemented to ensure consistent behavior across all ORMs.
     def define_methods!(mod)
       mod.module_eval <<-RUBY, __FILE__, __LINE__ + 1
         def #{name}
@@ -105,20 +114,27 @@ def #{name}
         end
 
         def #{name}=(new_value)
-          allowed_value_or_nil = self.class.enumerized_attributes[:#{name}].find_value(new_value)
-          allowed_value_or_nil = allowed_value_or_nil.value unless allowed_value_or_nil.nil?
+          allowed_value = self.class.enumerized_attributes[:#{name}].find_value(new_value)
+
+          value_to_assign = if allowed_value
+            allowed_value.value
+          elsif new_value == ''
+            nil
+          else
+            new_value
+          end
 
           if defined?(super)
-            super allowed_value_or_nil
+            super value_to_assign
           elsif respond_to?(:write_attribute, true)
-            write_attribute '#{name}', allowed_value_or_nil
+            write_attribute '#{name}', value_to_assign
           else
-            @#{name} = allowed_value_or_nil
+            @#{name} = value_to_assign
           end
 
           _enumerized_values_for_validation['#{name}'] = new_value.nil? ? nil : new_value.to_s
 
-          allowed_value_or_nil
+          value_to_assign
         end
 
         def #{name}_text

test/activerecord_test.rb

@@ -75,6 +75,7 @@
     t.string :foo
     t.boolean :newsletter_subscribed, default: true
     t.json :store_accessor_store_with_no_defaults
+    t.string :locale
   end
 
   create_table :documents do |t|
@@ -114,6 +115,12 @@ class User < ActiveRecord::Base
   enumerize :language, :in => [:en, :jp]
   enumerize :country_code, :in => [:us, :ca]
 
+  # normalizes is available in Rails 7.1+
+  if ActiveRecord.gem_version >= Gem::Version.new("7.1")
+    normalizes :locale, with: ->(value) { value.downcase.strip.presence }
+  end
+  enumerize :locale, :in => %i[de en pl]
+
   serialize :interests, type: Array
   enumerize :interests, :in => [:music, :sports, :dancing, :programming], :multiple => true
 
@@ -808,13 +815,13 @@ class AdminUser < User
 
     users = User.all.to_a
     expect(users.size).must_equal 3
-    
+
     expect(users[0].sex).must_equal 'male'
     expect(users[0].status).must_equal 'active'
-    
+
     expect(users[1].sex).must_equal 'female'
     expect(users[1].status).must_equal 'blocked'
-    
+
     expect(users[2].sex).must_equal 'male'
     expect(users[2].status).must_equal 'blocked'
   end
@@ -846,14 +853,28 @@ class AdminUser < User
 
     users = User.order(:id).to_a
     expect(users.size).must_equal 3
-    
+
     expect(users[0].sex).must_equal 'male'
     expect(users[0].status).must_equal 'active'
-    
+
     expect(users[1].sex).must_equal 'female'
     expect(users[1].status).must_equal 'blocked'
-    
+
     expect(users[2].sex).must_equal 'female'
     expect(users[2].status).must_equal 'blocked'
   end
+
+  # normalizes is available in Rails 7.1+
+  if ActiveRecord.gem_version >= Gem::Version.new("7.1")
+    it 'supports AR#normalizes class methods' do
+      User.delete_all
+      User.create!(locale: 'de')
+      expect(User.exists?(locale: ' DE ')).must_equal true
+    end
+
+    it 'supports AR#normalizes instance methods' do
+      user = User.new(locale: ' DE ')
+      expect(user.locale).must_equal 'de'
+    end
+  end
 end