[Admin] Fix rubocop offence and resources controller cleanup

admin/app/controllers/solidus_admin/resources_controller.rb

@@ -96,8 +96,6 @@
       resource_class.all
     end
 
-    def per_page; end
-
     def set_resource
       @resource ||= resource_class.find(params[:id]).tap do |resource|
           instance_variable_set("@#{resource_name}", resource)
@@ -157,5 +155,15 @@
     def after_destroy_path
       solidus_admin.send("#{plural_resource_name}_path", **search_filter_params)
     end
+
+    def blueprint
+      raise NotImplementedError,
+        "You must implement the blueprint method in #{self.class}"
+    end
+
+    def blueprint_view
+      raise NotImplementedError,
+        "You must implement the blueprint_view method in #{self.class}"
+    end
   end
 end

admin/spec/requests/solidus_admin/states_spec.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+
+RSpec.describe "SolidusAdmin::StatesController", type: :request do
+  let(:admin_user) { create(:admin_user) }
+
+  before do
+    allow_any_instance_of(SolidusAdmin::BaseController).to receive(:spree_current_user).and_return(admin_user)
+  end
+
+  describe "GET /index" do
+    before { create_list(:state, 3) }
+
+    it "serves json with a 200 OK status" do
+      get solidus_admin.states_path
+      expect(response.headers["Content-Type"]).to include("application/json")
+      expect(response).to have_http_status(:ok)
+      expect(JSON.parse(response.body).size).to eq(3)
+    end
+  end
+end