Broken chi.URLParam return empty string

[vorotech]

Reading the release notes, I assume the issue might be introduced in 5.0.12

Here is the code to demostrate

r.Route("/invoices", func(r chi.Router) {
      r.Route("/{invoiceNumber}", func(r chi.Router) {
	      r.Use(func(next http.Handler) http.Handler {
		      return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			      invoiceNumber := chi.URLParam(r, "invoiceNumber")
			      fmt.Println("Invoice Number in Middleware:", invoiceNumber) // Debugging line
			      ctx := context.WithValue(r.Context(), InvoiceCtxKey, invoiceNumber)
			      next.ServeHTTP(w, r.WithContext(ctx))
		      })
	      })
	      r.Use(h.InvoiceCtx)
	      r.Get("/", h.getInvoice)       // GET /invoices/123
	      r.Delete("/", h.deleteInvoice) // DELETE /invoices/123
      })
})

Specifically the line invoiceNumber := chi.URLParam(r, "invoiceNumber") will work as expected.

However, you can see the usage of r.Use(h.InvoiceCtx) where the same line of code is present - it will return "" emptry string every time.

func (h *Handler) InvoiceCtx(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		var invoice *domain.Invoice
		var err error

		if invoiceNumber := chi.URLParam(r, "invoiceNumber"); invoiceNumber != "" {
			invoice, err = h.invoices.GetInvoice(invoiceNumber)
		} else {
			render.Render(w, r, ErrNotFound)
			return
		}
		if err != nil {
			render.Render(w, r, ErrNotFound)
			return
		}

		ctx := context.WithValue(r.Context(), InvoiceCtxKey, invoice)
		next.ServeHTTP(w, r.WithContext(ctx))
	})
}

I don't understand the difference between usage the inline function with r.Use and actually specifying the fucntion, but it has a different execution behaviour.

Finally, if inside the InvoiceCtx replace chi.URLParam(r, "invoiceNumber") usage with r.PathValue("invoiceNumber") everything working as expected again.

[ConsoleTVs]

I have found out that chi.URLParam does not work and request.PathValue does...