Allow alternative class names

Changed: Pass class_name to the Null() or Void() methods with an alternative class name.

Author: saturnflyer

README.md

@@ -68,6 +68,19 @@ class User < ApplicationRecord
 end
 ```
 
+Customize the null class name:
+
+```ruby
+class User < ApplicationRecord
+  Null(class_name: "Guest")
+  class << self
+    alias_method :null, :guest
+  end
+end
+
+User.guest # returns a User::Guest instance
+```
+
 ### Void Objects
 
 While `Null` objects are singletons (one instance per model), `Void` objects are instantiable null objects that allow creating multiple instances with different attribute values.
@@ -115,6 +128,18 @@ Void objects support the same features as Null objects:
 - Custom methods via block syntax
 - Association handling
 - All ActiveRecord query methods (`null?`, `persisted?`, etc.)
+- Custom class names via `class_name:` parameter
+
+```ruby
+class Product < ApplicationRecord
+  Void(class_name: "Placeholder")
+  class << self
+    alias_method :void, :placeholder
+  end
+end
+
+Product.placeholder # returns a Product::Placeholder instance
+```
 
 Use `Null` when you need a single shared null object instance. Use `Void` when you need multiple null object instances with different attribute values.
 

lib/activerecord/null.rb

@@ -156,7 +156,7 @@ def initialize_attribute_methods
     #
     # @param inherit [Class] The class from which the Null object inherits attributes
     # @param assignments [Array] The attributes to assign to the null object
-    def Null(inherit = self, assignments = {}, &)
+    def Null(inherit = self, class_name: :Null, **assignments, &)
       if inherit.is_a?(Hash)
         assignments = inherit
         inherit = self
@@ -165,7 +165,7 @@ def Null(inherit = self, assignments = {}, &)
       null_class = create_null_class(inherit, assignments, singleton: true)
       null_class.class_eval(&) if block_given?
 
-      inherit.const_set(:Null, null_class)
+      inherit.const_set(class_name, null_class)
       inherit.define_singleton_method(:null) { null_class.instance }
     end
 
@@ -185,7 +185,7 @@ def Null(inherit = self, assignments = {}, &)
     #
     # @param inherit [Class] The class from which the Void object inherits attributes
     # @param assignments [Hash] The default attributes to assign to void objects
-    def Void(inherit = self, assignments = {}, &)
+    def Void(inherit = self, class_name: :Void, **assignments, &)
       if inherit.is_a?(Hash)
         assignments = inherit
         inherit = self
@@ -194,7 +194,7 @@ def Void(inherit = self, assignments = {}, &)
       void_class = create_null_class(inherit, assignments, singleton: false)
       void_class.class_eval(&) if block_given?
 
-      inherit.const_set(:Void, void_class)
+      inherit.const_set(class_name, void_class)
       inherit.define_singleton_method(:void) { |attributes = {}| void_class.new(attributes) }
     end