loading through base class

lib/has_aux_table/aux_table_config.rb

@@ -21,7 +21,15 @@ module HasAuxTable
     sig { params(main_model: ActiveRecord::Base).returns(ActiveRecord::Base) }
     def ensure_aux_target(main_model)
       aux_association = main_model.association(self.aux_association_name)
-      aux_association.target ||= aux_association.build
+      # binding.pry if main_model.persisted? && !aux_association.loaded?
+      aux_association.target ||=
+        (
+          if main_model.persisted?
+            aux_association.load_target
+          else
+            aux_association.build
+          end
+        )
     end
 
     sig do

spec/active_record/aux_table_spec.rb

@@ -38,7 +38,7 @@ RSpec.describe HasAuxTable do
         end
 
         t.create_aux :boat do |t|
-          t.string :boat_type
+          t.boolean :only_freshwater
         end
       end
 
@@ -771,6 +771,23 @@ RSpec.describe HasAuxTable do
     end
   end
 
+  it "loads the aux data separately when loaded from main class" do
+    car =
+      Car.create!(name: "Honda Civic", fuel_type: "gasoline", engine_size: 2.0)
+    boat = Boat.create!(name: "Yacht", only_freshwater: true)
+    expect(Vehicle.count).to eq(2)
+    expect(Car.count).to eq(1)
+    expect(Boat.count).to eq(1)
+
+    expect(count_queries { car = Vehicle.find(car.id) }).to eq(1)
+    expect(car.fuel_type).to eq("gasoline")
+    expect(car.engine_size).to eq(2.0)
+    expect(car.name).to eq("Honda Civic")
+
+    expect(count_queries { boat = Vehicle.find(boat.id) }).to eq(1)
+    expect(boat.only_freshwater).to eq(true)
+  end
+
   describe "namespaced models" do
     it "works with namespaced models" do
       fork1 =