Add spec to ensure middleware does not prevent default 404 rendering from Rails

Author: bknoles

spec/inertia/request_spec.rb

@@ -154,4 +154,12 @@
       end
     end
   end
+
+  describe 'a non existent route' do
+    it 'raises a 404 exception' do
+      expect {
+        get '/non_existent_route', headers: { 'X-Inertia' => true }
+      }.to raise_error(ActionController::RoutingError,  /No route matches/)
+    end
+  end
 end