package main import ( "io/ioutil" "net" "net/http" "net/http/httptest" "net/url" "testing" ) func TestNewReverseProxy(t *testing.T) { backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { w.WriteHeader(200) hostname, _, _ := net.SplitHostPort(r.Host) w.Write([]byte(hostname)) })) defer backend.Close() backendURL, _ := url.Parse(backend.URL) backendHostname := "upstream.127.0.0.1.xip.io" _, backendPort, _ := net.SplitHostPort(backendURL.Host) backendHost := net.JoinHostPort(backendHostname, backendPort) proxyURL, _ := url.Parse(backendURL.Scheme + "://" + backendHost + "/") proxyHandler := NewReverseProxy(proxyURL) frontend := httptest.NewServer(proxyHandler) defer frontend.Close() getReq, _ := http.NewRequest("GET", frontend.URL, nil) res, _ := http.DefaultClient.Do(getReq) bodyBytes, _ := ioutil.ReadAll(res.Body) if g, e := string(bodyBytes), backendHostname; g != e { t.Errorf("got body %q; expected %q", g, e) } }