Raise error when generating attribute with dangerous name

railties/CHANGELOG.md

@@ -1,3 +1,15 @@
+*   Raise error when generating attribute with dangerous name.
+
+    The following will now raise an error as `save` and `hash` are already
+    defined by Active Record.
+
+    ```bash
+    bin/rails generate model Post save
+    bin/rails generate model Post hash
+    ```
+
+    *Petrik de Heus*
+
 ## Rails 7.1.0.beta1 (September 13, 2023) ##
 
 *   Add ability to show slow tests to the test runner

railties/lib/rails/generators/generated_attribute.rb

@@ -43,6 +43,10 @@ def parse(column_definition)
           type, attr_options = *parse_type_and_options(type)
           type = type.to_sym if type
 
+          if dangerous_name?(name)
+            raise Error, "Could not generate field '#{name}', as it is already defined by Active Record."
+          end
+
           if type && !valid_type?(type)
             raise Error, "Could not generate field '#{name}' with unknown type '#{type}'."
           end
@@ -60,6 +64,10 @@ def parse(column_definition)
           new(name, type, index_type, attr_options)
         end
 
+        def dangerous_name?(name)
+          ActiveRecord::Base.dangerous_attribute_method?(name)
+        end
+
         def valid_type?(type)
           DEFAULT_TYPES.include?(type.to_s) ||
             ActiveRecord::Base.connection.valid_type?(type)

railties/test/generators/generated_attribute_test.rb

@@ -17,6 +17,14 @@ def teardown
     Rails.application.config.active_record.belongs_to_required_by_default = @old_belongs_to_required_by_default
   end
 
+  def test_field_name_with_dangerous_attribute_raises_error
+    e = assert_raise Rails::Generators::Error do
+      create_generated_attribute :string, :save
+    end
+    message = "Could not generate field 'save', as it is already defined by Active Record."
+    assert_match message, e.message
+  end
+
   def test_field_type_returns_number_field
     assert_field_type :integer, :number_field
   end