Use different namespace for proxy calls

activemodel/CHANGELOG.md

@@ -1,3 +1,9 @@
+*   Use different cache namespace for proxy calls
 
+    Models can currently have different attribute bodies for the same method
+    names, leading to conflicts. Adding a new namespace `:active_model_proxy`
+    fixes the issue.
+
+    *Chris Salzberg*
 
 Please check [7-0-stable](https://github.com/rails/rails/blob/7-0-stable/activemodel/CHANGELOG.md) for previous changes.

activemodel/lib/active_model/attribute_methods.rb

@@ -319,7 +319,7 @@ def define_attribute_method(attr_name, _owner: generated_attribute_methods)
               if respond_to?(generate_method, true)
                 send(generate_method, attr_name.to_s, owner: owner)
               else
-                define_proxy_call(owner, method_name, matcher.target, matcher.parameters, attr_name.to_s, namespace: :active_model)
+                define_proxy_call(owner, method_name, matcher.target, matcher.parameters, attr_name.to_s, namespace: :active_model_proxy)
               end
             end
           end

activemodel/test/cases/attributes_test.rb

@@ -24,6 +24,33 @@ class GrandchildModelForAttributesTest < ChildModelForAttributesTest
       attribute :string_field, default: "default string"
     end
 
+    class ModelWithGeneratedAttributeMethods
+      include ActiveModel::Attributes
+
+      attribute :foo
+    end
+
+    class ModelWithProxiedAttributeMethods
+      include ActiveModel::AttributeMethods
+
+      attribute_method_suffix "="
+
+      define_attribute_method(:foo)
+
+      def attribute=(_, _)
+      end
+    end
+
+    test "models that proxy attributes do not conflict with models with generated methods" do
+      ModelWithGeneratedAttributeMethods.new
+
+      model = ModelWithProxiedAttributeMethods.new
+
+      assert_nothing_raised do
+        model.foo = "foo"
+      end
+    end
+
     test "properties assignment" do
       data = ModelForAttributesTest.new(
         integer_field: "2.3",