V8 JavaScript middleware for Go (golang)

pushrod.go

package main

import (
	"fmt"
	"net/http"
	"os"
	"reflect"

	v8 "github.com/idada/v8.go"
	"github.com/nbio/hitch"
)

func main() {
	h := hitch.New()
	h.Use(Logger)
	h.Use(Pushrod)
	h.Get("/*extra", http.HandlerFunc(Handler))

	port := os.Getenv("PORT")
	if port == "" {
		port = "8001"
	}
	http.ListenAndServe("127.0.0.1:"+port, h.Handler())
}

func Handler(w http.ResponseWriter, req *http.Request) {
	w.Header().Set("Content-Type", "text/plain")
	fmt.Fprintf(w, "%s %s\n", req.Method, req.URL.Path)
}

func Logger(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
		fmt.Printf("%s %s\n", req.Method, req.URL.String())
		next.ServeHTTP(w, req)
	})
}

type Request struct {
	Path string `js-field:"path"`
}

func Pushrod(next http.Handler) http.Handler {
	engine := v8.NewEngine()

	global := engine.NewObjectTemplate()
	global.Bind("Request", Request{})

	script := engine.Compile([]byte(`
		"JavaScript says: " + request.path
	`), nil)

	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
		context := engine.NewContext(global)
		context.Scope(func(cs v8.ContextScope) {
			r := &Request{
				Path: req.URL.Path,
			}
			cs.Global().SetProperty("request", engine.GoValueToJsValue(reflect.ValueOf(r)))
			result := cs.Run(script)
			fmt.Println(result.ToString())
		})
		next.ServeHTTP(w, req)
	})
}