I’m using Go’s standard library and trying to register multiple HTTP handlers with http.NewServeMux. However, I’ve encountered an issue where only the route /reservation/cancel is registered, while other routes ending with / (like /) are not.

Here’s the code I’m using to register the handlers:

func (dep *ReservationHandler) Register() {
    ware := middleware.RequestBodyMiddleware[model.ReservationPayload]{Logger: dep.logger}
    mux := http.NewServeMux()

    mux.HandleFunc("GET /", dep.availableDates)
    mux.Handle("POST /", ware.RequestBody(http.HandlerFunc(dep.create)))
    mux.HandleFunc("POST /cancel/{reservation_id}", dep.cancel)

    dep.mux.Handle("/reservation/", http.StripPrefix("/reservation", mux))

}

Note that when I use the following approach, everything works as expected:

func (dep *ReservationHandler) Register() {
    ware := middleware.RequestBodyMiddleware[model.ReservationPayload]{Logger: dep.logger}

    dep.mux.HandleFunc("GET /reservation", dep.availableDates)
    dep.mux.Handle("POST /reservation", ware.RequestBody(http.HandlerFunc(dep.create)))
    dep.mux.HandleFunc("POST /reservation/cancel/{reservation_id}", dep.cancel)
}

Why is it that the routes with / at the end aren’t registered in the first example, but the ones with explicit /reservation work fine?