Simple panic middleware

panicmiddlware.go

package main

import (
	"log"
	"net/http"
)

func panicMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		defer func() {
			if e := recover(); e != nil {
				w.WriteHeader(http.StatusInternalServerError)
				if s, ok := e.(string); ok {
					w.Write([]byte(s))
				}
			}
		}()
		next.ServeHTTP(w, r)
	})
}

func main() {
	server := &http.Server{
		Addr: ":8080",
		Handler: panicMiddleware(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			switch r.RequestURI {
			case "/error":
				panic("something bad happened")
			default:
				w.Write([]byte("Hello World!\n"))
			}
		})),
	}
	log.Fatal(server.ListenAndServe())
}