Ensure private attributes works with child classes

lib/extensions/ar_private_attribute.rb

@@ -9,6 +9,8 @@ module ArPrivateAttribute
     # @param [String|Symbol] attribute name of attribute to be private from the api and reporting
     # this attribute is accessible to all ruby methods. But it is not advertised.
     # we do this when deprecating an attribute or when introducing an internal attribute
+    #
+    # NOTE: only use in class definitions, or child classes will be broken
     def private_attribute(attribute)
       self.private_attribute_names += [attribute.to_s]
     end

spec/lib/extensions/ar_private_attribute_spec.rb

@@ -2,6 +2,7 @@
   # NOTE: ApplicationRecord already included ArPrivateAttribute
   let(:klass) { Class.new(ApplicationRecord) { self.table_name = "vms" } }
   let(:other_klass) { Class.new(ApplicationRecord) { self.table_name = "vms" } }
+  let(:child_klass) { Class.new(klass) }
 
   context ".public_attribute_names" do
     it "shows regular attributes" do
@@ -13,10 +14,51 @@
       expect(klass.public_attribute_names).not_to include("type")
     end
 
+    it "shows virtual attributes" do
+      klass.virtual_attribute :superb, :string
+      expect(klass.public_attribute_names).to include("superb")
+    end
+
+    it "hides private virtual attributes" do
+      klass.virtual_attribute :superb, :string
+      klass.private_attribute :superb
+      expect(klass.public_attribute_names).not_to include("superb")
+    end
+
     it "only hides attributes for the specified class" do
       klass.private_attribute :type
       expect(other_klass.public_attribute_names).to include("type")
     end
+
+    context "child class" do
+      it "shows regular attributes" do
+        expect(child_klass.public_attribute_names).to include("type")
+      end
+
+      it "hides attributes that are private in parent class" do
+        klass.private_attribute :type
+        expect(child_klass.public_attribute_names).not_to include("type")
+      end
+
+      it "hides virtual attributes that are private in the parent class" do
+        klass.virtual_attribute :superb, :string
+        klass.private_attribute :superb
+        expect(child_klass.public_attribute_names).not_to include("superb")
+      end
+
+      it "hides attributes that are private in class and parent class" do
+        klass.private_attribute :type
+        child_klass.private_attribute :name
+        expect(child_klass.public_attribute_names).not_to include("type")
+        expect(child_klass.public_attribute_names).not_to include("name")
+      end
+
+      it "hides attribute only for class and below" do
+        child_klass.private_attribute :name
+        expect(klass.public_attribute_names).to include("name")
+        expect(child_klass.public_attribute_names).not_to include("name")
+      end
+    end
   end
 
   context ".private_attribute_names" do
@@ -33,5 +75,23 @@
       klass.private_attribute :type
       expect(other_klass.private_attribute_names).not_to include("type")
     end
+
+    context "child class" do
+      it "starts with no private attributes" do
+        expect(child_klass.private_attribute_names).to be_empty
+      end
+
+      it "hides attributes that are private in parent class" do
+        klass.private_attribute :type
+        expect(child_klass.private_attribute_names).to include("type")
+      end
+
+      it "hides attributes that are private in parent class" do
+        klass.private_attribute :type
+        child_klass.private_attribute :name
+        expect(child_klass.private_attribute_names).to include("type")
+        expect(child_klass.private_attribute_names).to include("name")
+      end
+    end
   end
 end

spec/models/mixins/deprecation_mixin_spec.rb

@@ -7,4 +7,11 @@
       expect(Host.arel_attribute(:address).name).to eq("hostname") # typically this is a symbol. not perfect but it works
     end
   end
+
+  # Host.deprecate_attribute :address, :hostname
+  context ".public_attribute_names" do
+    it "hides deprecate_attribute columns" do
+      expect(Host.public_attribute_names).not_to include("address")
+    end
+  end
 end