ESP8266WebServer handler that returns SPIFFS directory list

handleDirList.cpp

//  server.on("/dir", HTTP_GET, handleDirList);
  
void handleDirList() {
  SPIFFS.begin();
  String str = "";
  Dir dir = SPIFFS.openDir("/");
  while (dir.next()) {
    str += dir.fileName();
    str += " ";
    str += dir.fileSize();
    str += " bytes\r\n";
  }
  server.send(200, "text/plain", str);
}