Golang custom ServeHTTP status logging

I am building my own web framework, and I have faced with problem, when I try to log the request with response status code, i got err: invalid memory address or nil pointer dereference

My ServeHTTP func:

func (r *Router) ServeHTTP(w http.ResponseWriter, req *http.Request) {

    handler := r.getHandler(req.Method, req.URL.Path)
    if handler == nil {
        notFoundHandler(w, req)
        return
    }
    done := make(chan struct{})

    reqStruct := newReqStruct(w, req)

    go func() {
        handler(reqStruct)
        done <- struct{}{}
        close(done)
    }()
    <-done
    logger.logRequest(req.URL.Path, req.Method, req.Response.StatusCode)

}

>Solution :

This line:

    logger.logRequest(req.URL.Path, req.Method, req.Response.StatusCode)

req.Response will only be populated for HTTP redirects. In this case, it will be nil.

If you want to capture the response code, write a wrapper response writer and implement WriteHeader to capture the response code.