Test custom controller names

test/custom_controller_name_test.rb

@@ -0,0 +1,19 @@
+require "test_helper"
+
+class CustomControllerNameTest < ActionDispatch::IntegrationTest
+  controller(ApplicationController, controller_name: "CustomsController") do
+    def index
+      render plain: self.class.name
+    end
+  end
+
+  test "route matches controller name" do
+    get "/customs"
+    assert_equal(200, response.status)
+  end
+
+  test "controller name is correct" do
+    get "/customs"
+    assert_equal("CustomsController", response.body)
+  end
+end