test: Add column_names test

Author: hatsu38

spec/active_yaml/aliases_spec.rb

@@ -43,6 +43,11 @@ class KeyProduct < ActiveYaml::Base
         model.all
         expect(model.field_names).to match_array [:name, :flavor, :price]
       end
+
+      it 'excludes them from column_names' do
+        model.all
+        expect(model.column_names).to match_array ["name", "flavor", "price"]
+      end
     end
   end
 
@@ -70,6 +75,11 @@ class KeyProduct < ActiveYaml::Base
         model.all
         expect(model.field_names).to match_array [:name, :flavor, :price, :slogan, :key]
       end
+
+      it 'excludes them from column_names' do
+        model.all
+        expect(model.column_names).to match_array ["name", "flavor", "price", "slogan", "key"]
+      end
     end
   end