Validate url_pattern format in control API append operation

Closes: #38

Co-authored-by: César Gallego Rodríguez <cesar.gallego.next@bbva.com>

internal/server/control/control.go

@@ -70,6 +70,10 @@ func listRoutes(res http.ResponseWriter, req *http.Request) {
 var funcAdd func(model.Route) model.Route = user.Routes.Append
 var idGenerator = uuid.NewUUID
 
+var pathValidator func(string) error = func(path string) error {
+	return mux.NewRouter().NewRoute().BuildOnly().Path(path).GetError()
+}
+
 func addRoute(res http.ResponseWriter, req *http.Request) {
 	var route model.Route
 
@@ -88,6 +92,12 @@ func addRoute(res http.ResponseWriter, req *http.Request) {
 		return
 	}
 
+	err = pathValidator(route.Pattern)
+	if err != nil {
+		res.WriteHeader(http.StatusUnprocessableEntity)
+		return
+	}
+
 	id, err := idGenerator()
 	if err != nil {
 		res.WriteHeader(http.StatusInternalServerError)