Wrapping a handler with a middleware that has parameters with Go-chi - http

Question

i've been trying to implement this tutorial with go-chi and especially the part about wrapping / passing an argument to a wrapper.
My goal is to be able to wrap some specific routes with a middleware with custom parameters for that route instead of having middleware that are " global " to all my routes but i'm having issues doing it.
package main
import (
"context"
"io"
"net/http"
"github.com/go-chi/chi"
"github.com/go-chi/chi/middleware"
)
func main() {
r := chi.NewRouter()
r.Use(middleware.Logger)
r.Get("/user", MustParams(sayHello, "key", "auth"))
http.ListenAndServe(":3000", r)
}
func sayHello(w http.ResponseWriter, r *http.Request) {
w.Write([]byte("hi"))
}
func MustParams(h http.Handler, params ...string) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
q := r.URL.Query()
for _, param := range params {
if len(q.Get(param)) == 0 {
http.Error(w, "missing "+param, http.StatusBadRequest)
return // exit early
}
}
h.ServeHTTP(w, r) // all params present, proceed
})
}
i'm getting cannot use sayHello (type func(http.ResponseWriter, *http.Request)) as type http.Handler in argument to MustParams: func(http.ResponseWriter, *http.Request) does not implement http.Handler (missing ServeHTTP method)
and if i try to type assert it doing r.Get("/user", MustParams(http.HandleFunc(sayHello), "key", "auth"))
i get the error cannot use MustParams(http.HandleFunc(sayHello), "key", "auth") (type http.Handler) as type http.HandlerFunc in argument to r.Get: need type assertion
I can't seem to find a way to make it work or to be able to wrapping a single route with a middleware.

Answer 1

There's a function http.HandleFunc and then there's a type http.HandlerFunc. You're using the former but you need the latter.
r.Get("/user", MustParams(http.HandlerFunc(sayHello), "key", "auth"))