package metrics

import (
	"bufio"
	"net"
	"net/http"
	"net/http/httptest"
	"testing"
)

type hijackRecorder struct {
	*httptest.ResponseRecorder
}

func (h *hijackRecorder) Hijack() (net.Conn, *bufio.ReadWriter, error) {
	return nil, nil, nil
}

func TestMiddlewarePreservesHijacker(t *testing.T) {
	var seen http.ResponseWriter
	handler := Middleware(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		seen = w
	}))

	handler.ServeHTTP(&hijackRecorder{httptest.NewRecorder()}, httptest.NewRequest(http.MethodGet, "/", nil))

	if _, ok := seen.(http.Hijacker); !ok {
		t.Fatal("middleware stripped http.Hijacker: WebSocket upgrades will fail")
	}
}