Pretty print middleware for Go

pretty_print_middleware.go

import "net/http/httptest"


func (a *IndentJSONMiddleware) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	rec := httptest.NewRecorder()
	a.handler.ServeHTTP(rec, r)

	for k, v := range rec.Header() {
		w.Header()[k] = v
	}

	var pretty bytes.Buffer
	json.Indent(&pretty, rec.Body.Bytes(), "", "    ")
	r.Header.Set("Content-Length", strconv.Itoa(pretty.Len()))
	w.Header().Set("Content-Type", "application/json")
	w.Write(pretty.Bytes())
}