Example of wrapping both Gorilla/Mux and httprouter while keeping route params in golang

dual_router_wrapper.go

package main

import (
	"net/http"
	"reflect"

	"github.com/gorilla/mux"
	"github.com/julienschmidt/httprouter"
)

func WrapHTTPRouter() func(interface{}) httprouter.Handle {
	return func(function interface{}) httprouter.Handle {
		return func(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
			get := func(name string) string {
				return ps.ByName(name)
			}

			Wrap(function, w, r, get)
		}
	}
}

func WrapGorillaMux() func(interface{}) http.HandlerFunc {
	return func(function interface{}) http.HandlerFunc {
		return func(w http.ResponseWriter, r *http.Request) {
			params := mux.Vars(r)

			get := func(name string) string {
				if param, ok := params[name]; ok {
					return param
				}
				return ""
			}

			Wrap(function, w, r, get)
		}
	}
}

type DemoObject struct {
	Name string
}

func Wrap(function interface{}, w http.ResponseWriter, r *http.Request, params func(string) string) {

	object := DemoObject{params("name")}
	funcValue := reflect.ValueOf(function)

	in := []reflect.Value{
		reflect.ValueOf(w),
		reflect.ValueOf(r),
		reflect.ValueOf(object),
	}

	funcValue.Call(in)
}

func main() {

}

wrapper_test.go

package main

import (
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"

	"github.com/gorilla/mux"
	"github.com/julienschmidt/httprouter"
)

func TestGorilla(t *testing.T) {

	var req *http.Request

	// Service we will be wrapping
	controller := func(w http.ResponseWriter, r *http.Request, in struct{ Name string }) {
		w.Write([]byte(in.Name))
	}

	// Create HTTP mux/router
	// mux := httprouter.New()
	router := mux.NewRouter()

	// wrapper := WrapHTTPRouter()
	wrapper := WrapGorillaMux()

	// Our route
	// router.GET("/:name", wrapper(controller))
	router.HandleFunc("/{name}", wrapper(controller))

	req, err := http.NewRequest("GET", "/john", nil)
	if err != nil {
		t.Fatal(err)
	}

	rr := httptest.NewRecorder()

	router.ServeHTTP(rr, req)

	if status := rr.Code; status != http.StatusOK {
		t.Errorf("Wrong status code: got %v want %v", status, http.StatusOK)
	}

	response := strings.TrimSpace(rr.Body.String())
	want := `john`
	if response != want {
		t.Errorf("Wrong response:\ngot %s\nwant %s", response, want)
	}

}

func TestHTTPRouter(t *testing.T) {

	var req *http.Request

	// Service we will be wrapping
	controller := func(w http.ResponseWriter, r *http.Request, in struct{ Name string }) {
		w.Write([]byte(in.Name))
	}

	// Create HTTP mux/router
	router := httprouter.New()

	wrapper := WrapHTTPRouter()

	// Our route
	router.GET("/:name", wrapper(controller))

	req, err := http.NewRequest("GET", "/john", nil)
	if err != nil {
		t.Fatal(err)
	}

	rr := httptest.NewRecorder()

	router.ServeHTTP(rr, req)

	if status := rr.Code; status != http.StatusOK {
		t.Errorf("Wrong status code: got %v want %v", status, http.StatusOK)
	}

	response := strings.TrimSpace(rr.Body.String())
	want := `john`
	if response != want {
		t.Errorf("Wrong response:\ngot %s\nwant %s", response, want)
	}

}