Standalone DTO inheritance

spec/ar2dto/dto_spec.rb

@@ -0,0 +1,41 @@
+# frozen_string_literal: true
+
+RSpec.describe AR2DTO::DTO do
+  let(:klass) do
+    Class.new(described_class[User]) do
+      def self.name
+        "AnonymousDTO"
+      end
+    end
+  end
+
+  let(:attributes) do
+    {
+      first_name: "Sandy",
+      last_name: "Doe",
+      email: "sandy@example.com",
+      birthday: Time.new(1995, 8, 25),
+      status: "pending"
+    }
+  end
+  let(:user) { User.new(attributes) }
+
+  context "initialized with value attributes" do
+    subject { klass.new(user.attributes) }
+
+    it "responds to defined methods" do
+      expect(subject.first_name).to eq("Sandy")
+    end
+
+    it "implements equality" do
+      expect(subject).to eq(klass.new(user.attributes))
+      expect(subject).to_not eq(klass.new(user.attributes.merge(first_name: "Other")))
+    end
+
+    it "does not respond to other methods" do
+      expect(subject).to_not respond_to(:undefined_method)
+    end
+
+    it_behaves_like "ActiveModel"
+  end
+end