Fix class_name when in a namespace

lib/ar2dto/model_config.rb

@@ -13,26 +13,25 @@ def setup_config(configs)
     end
 
     def except
-      configs["except"]
+      @except ||= configs["except"]
     end
 
     def class_name
-      configs["class_name"] ||
-        model_name.sub(/#{configs["replace_suffix"]["from"]}$/, configs["replace_suffix"]["to"].to_s)
+      @class_name ||= namespaced_class_name.split("::").last
     end
 
     def namespace
-      @namespace ||= model.name.deconstantize.presence&.constantize || Object
+      @namespace ||= namespaced_class_name.deconstantize.presence&.constantize || Object
     end
 
     def namespaced_class_name
-      "#{namespace}::#{class_name}"
+      @namespaced_class_name ||= configs["class_name"] || model_name_replaced_suffix
     end
 
     private
 
-    def model_name
-      model.name.split("::").last
+    def model_name_replaced_suffix
+      model.name.sub(/#{configs["replace_suffix"]["from"]}$/, configs["replace_suffix"]["to"].to_s)
     end
   end
 end

spec/ar2dto/options_spec.rb

@@ -31,6 +31,12 @@ def self.name
     it "respects the custom class_name" do
       expect(Car.new.to_dto).to be_a(VehicleDTO)
     end
+
+    context "with a namespace" do
+      it "respects the custom class_name" do
+        expect(Payments::Transaction.new.to_dto).to be_a(Core::TransactionDTO)
+      end
+    end
   end
 
   describe "option replace_suffix" do

spec/spec_helper.rb

@@ -11,6 +11,8 @@
 require "support/active_model"
 require "support/schema"
 require "support/fixtures/car"
+require "support/fixtures/core"
+require "support/fixtures/payments/transaction"
 require "support/fixtures/person_dto"
 require "support/fixtures/person"
 require "support/fixtures/shop/order"

spec/support/fixtures/core.rb

@@ -0,0 +1,4 @@
+# frozen_string_literal: true
+
+module Core
+end

spec/support/fixtures/payments/transaction.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+module Payments
+  class Transaction < ActiveRecord::Base
+    self.table_name = "payments_transactions"
+
+    belongs_to :shop_order, class_name: "Shop::Order"
+
+    has_dto class_name: "Core::TransactionDTO"
+  end
+end

spec/support/schema.rb

@@ -32,4 +32,10 @@
 
     t.timestamps
   end
+
+  create_table :payments_transactions, force: true do |t|
+    t.bigint :shop_order_id
+
+    t.string :result
+  end
 end