Correct error response content length

handler.go

@@ -459,11 +459,11 @@ func (handler *Handler) sendError(w http.ResponseWriter, r *http.Request, err er
 	if r.Method == "HEAD" {
 		reason = ""
 	}
-
+	reason += "\n"
 	w.Header().Set("Content-Type", "text/plain")
 	w.Header().Set("Content-Length", strconv.Itoa(len(reason)))
 	w.WriteHeader(status)
-	w.Write([]byte(err.Error()))
+	w.Write([]byte(reason))
 }
 
 // Make an absolute URLs to the given upload id. If the base path is absolute

head_test.go

@@ -3,6 +3,7 @@ package tusd
 import (
 	"net/http"
 	"os"
+	"strconv"
 	"testing"
 )
 
@@ -46,8 +47,15 @@ func TestHead(t *testing.T) {
 			"Cache-Control":   "no-store",
 		},
 	}).Run(handler, t)
+}
 
-	(&httpTest{
+func TestHead404(t *testing.T) {
+	handler, _ := NewRoutedHandler(Config{
+		BasePath:  "https://buy.art/",
+		DataStore: headStore{},
+	})
+
+	resp := (&httpTest{
 		Name:   "Non-existing file",
 		Method: "HEAD",
 		URL:    "no",
@@ -55,5 +63,16 @@ func TestHead(t *testing.T) {
 			"Tus-Resumable": "1.0.0",
 		},
 		Code:    http.StatusNotFound,
+		ResBody: "",
 	}).Run(handler, t)
+
+	body := string(resp.Body.Bytes())
+	if body != "\n" {
+		t.Errorf("Expected body to be empty. Got: %v", body)
+	}
+
+	contentLength := resp.Header().Get("Content-Length")
+	if contentLength != strconv.Itoa(len(body)) {
+		t.Errorf("Expected content length header to match body length. Got: %v", contentLength)
+	}
 }

routed_handler_test.go

@@ -44,7 +44,7 @@ type httpTest struct {
 	ResHeader map[string]string
 }
 
-func (test *httpTest) Run(handler http.Handler, t *testing.T) {
+func (test *httpTest) Run(handler http.Handler, t *testing.T) *httptest.ResponseRecorder {
 	t.Log(test.Name)
 
 	req, _ := http.NewRequest(test.Method, test.URL, test.ReqBody)
@@ -77,6 +77,8 @@ func (test *httpTest) Run(handler http.Handler, t *testing.T) {
 	if test.ResBody != "" && string(w.Body.Bytes()) != test.ResBody {
 		t.Errorf("Expected '%s' as body (got '%s'", test.ResBody, string(w.Body.Bytes()))
 	}
+
+	return w
 }
 
 type methodOverrideStore struct {