Crude HTTP Middleware Implementation

middleware.go

package main

import(
	"net/http"
	"net/http/httptest"
	"log"
	"io/ioutil"
	"fmt"
)

import (
	"github.com/julienschmidt/httprouter"
)

func main(){
	r := httprouter.New()
	mIndex := -1
	var middlewares []httprouter.Handle
	var handler httprouter.Handle
	var writer http.ResponseWriter
	var request *http.Request
	var params httprouter.Params
	next := func() {
		log.Println("next")
		mIndex++
		if mIndex < len(middlewares) {
			middlewares[mIndex](writer, request, params)
		} else {
			handler(writer, request, params)
		}
	}
	wrapper := func(h httprouter.Handle) httprouter.Handle{
		log.Println("wrapper")
		return func(w http.ResponseWriter, r *http.Request, p httprouter.Params){
			handler = h
			writer = w
			request = r
			params = p
			next()
		}
	}
	middlewares = append(middlewares, func(w http.ResponseWriter, _ *http.Request, _ httprouter.Params){
		log.Println("m1")
		fmt.Fprint(w, "m1")
		next()
	})
	middlewares = append(middlewares, func(w http.ResponseWriter, _ *http.Request, _ httprouter.Params){
		log.Println("m2")
		fmt.Fprint(w, "m2")
		next()
	})
	r.GET("/1", wrapper(func(w http.ResponseWriter, _ *http.Request, _ httprouter.Params){
		log.Println("r1")
		fmt.Fprint(w, "r1")
	}))
	r.GET("/2", wrapper(func(w http.ResponseWriter, _ *http.Request, _ httprouter.Params){
		log.Println("r2")
		fmt.Fprint(w, "r2")
	}))
	server := httptest.NewServer(r)
	defer server.Close()

	res, err := http.Get(server.URL+"/1")
	if err != nil {
		log.Fatal(err)
	}
	greeting, err := ioutil.ReadAll(res.Body)
	res.Body.Close()
	if err != nil {
		log.Fatal(err)
	}

	fmt.Printf("final %s", greeting)
}