fix not working stuff

handler.go

@@ -57,7 +57,7 @@ func HandleFiles(path string, options HandlerOptions, mux *http.ServeMux) {
 			clientVersion:       options.ClientVersion,
 		})
 		if options.ActivateLiveReloading {
-			mux.Handle("/_livereloader_", reloader{
+			http.Handle("/_livereloader_", reloader{
 				clientVersion: options.ClientVersion,
 			})
 		}

helper.go

@@ -2,6 +2,7 @@ package spa_handler
 
 import (
 	"bytes"
+	"fmt"
 	"io"
 	"io/fs"
 	"net/http"
@@ -16,11 +17,11 @@ func tryToDeliverFile(file fs.File, path string, w http.ResponseWriter, r *http.
 		http.Error(w, "can not read file", http.StatusInternalServerError)
 		return
 	}
-	modified := []byte{}
+	merge := bytes.NewBuffer([]byte{})
 	for _, a := range appender {
-		modified = append(modified, []byte(a)...)
+		merge.WriteString(a)
 	}
-	modified = append(modified, content...)
+	newContent := strings.Replace(string(content), "</html>", fmt.Sprintf("%s\n</html>", merge.String()), 1)
 
 	stats, statErr := file.Stat()
 	if statErr != nil {
@@ -33,7 +34,7 @@ func tryToDeliverFile(file fs.File, path string, w http.ResponseWriter, r *http.
 	}
 	contentType = getContentTypeDetail(contentType, stats)
 
-	fileSeeker := bytes.NewReader(modified)
+	fileSeeker := bytes.NewReader([]byte(newContent))
 	w.Header().Set("Content-Type", contentType)
 	http.ServeContent(w, r, path, time.Now(), fileSeeker)
 }

reloader.go

@@ -9,8 +9,8 @@ import (
 
 func clientScript(clientVersion string) string {
 	return fmt.Sprintf(`
-<!-- [spa_handler] Live Reloading Script Start -->
 <script type="application/javascript">
+	// [spa_handler] live reload script
 	function spaHandlerLiveReloaderConnect() {
 		const ws = new WebSocket("/_livereloader_");
 		ws.onopen = function() {
@@ -38,11 +38,8 @@ func clientScript(clientVersion string) string {
 			console.warning('[spa_handler]: something was wrong with websocket connection! ', err)
 		};
 	}
-	document.onload = function() {
+	spaHandlerLiveReloaderConnect();
-		spaHandlerLiveReloaderConnect();
-	};
 </script>
-<!-- [spa_handler] Live Reloading Script End -->
 `, clientVersion)
 }