Server returning 400 when user exists - http

Question

I'm working on some tests in Go and I have spent the past 2 days trying to make it work but I couldn't. My problem is that the test returns 400 even when the user does exist.
This is my getUser function
func (handler *UserHandler) getUser(w http.ResponseWriter, ID int) {
logfile, err := os.OpenFile("events.log", os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
if err != nil {
log.Fatalf("Error opening file: %v", err)
}
defer logfile.Close()
log.SetOutput(logfile)
user := db.Fetch(ID)
userJSON, err := json.Marshal(user)
if err != nil {
log.Printf("Error while marshaling the user into JSON: %v", err)
return
}
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(http.StatusOK)
// userJSON is sent as http Response
w.Write(userJSON)
}
This is my UserHandler
type UserHandler struct{}
func (handle *UserHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
var head string
head, r.URL.Path = ShiftPath(r.URL.Path)
id, err := strconv.Atoi(head)
if err != nil {
http.Error(w, fmt.Sprintf("Invalid user ID %q", head), http.StatusBadRequest)
return
}
switch r.Method {
case "GET":
handle.getUser(w, id)
default:
http.Error(w, "Only GET is allowed", http.StatusMethodNotAllowed)
}
}
func ShiftPath(p string) (head, tail string) {
p = path.Clean("/" + p)
i := strings.Index(p[1:], "/") + 1
if i <= 0 {
return p[1:], "/"
}
return p[1:i], p[i:]
}
And this is my test
func TestGetUser(t *testing.T) {
handler := new(UserHandler)
mux := http.NewServeMux()
mux.HandleFunc("/user/", handler.ServeHTTP)
writer := httptest.NewRecorder()
request, _ := http.NewRequest("GET", "/user/12", nil)
mux.ServeHTTP(writer, request)
if writer.Code != 200 {
t.Errorf("Response code is %v", writer.Code)
}
}

Answer 1

Issue with code ====> id, err := strconv.Atoi(head)
Due to error you see a return and hence you see 400 error.
Have your server code fully functional with valid logic.
Suggestion: Always print or debug line by line. You can find the issue and root cause.