spec for multiple plucked columns

lib/has_aux_table/relation_extensions.rb

@@ -119,7 +119,7 @@ module HasAuxTable
         )
 
       pluck_method = relation_class.instance_method(:pluck)
-      relation_class.send(:define_method, :pluck) do |column_names|
+      relation_class.send(:define_method, :pluck) do |*column_names|
         T.bind(self, ActiveRecord::Relation)
         if (predicates = Util.try_relation_optimization(self, aux_config))
           aux_relation = aux_config.aux.klass.where(predicates)

spec/loading_optimizations_spec.rb

@@ -86,6 +86,19 @@ RSpec.describe "loading optimizations" do
 
         it_behaves_like "queries both tables"
       end
+
+      context "multiple columns" do
+        before do
+          @queries =
+            SpecHelper.capture_queries do
+              expect(Car.pluck(:fuel_type, :engine_size)).to eq(
+                [["gasoline", 2.0], ["hybrid", 1.5], ["electric", 1.8]]
+              )
+            end
+        end
+
+        it_behaves_like "queries only the aux table"
+      end
     end
 
     describe "maximum" do