如何在 Firefox 中过滤掉上传处理程序中的目录？

var dropArea = document.getElementById("dropArea");
var output = document.getElementById("result");
var ul = output.querySelector("ul");

function dragHandler(event) {
  event.stopPropagation();
  event.preventDefault();

  dropArea.className = "area drag";
}

function filesDroped(event) {
  event.stopPropagation();
  event.preventDefault();
  dropArea.className = "area";

  var uploadFile = function(file, path) {
    // handle file uploading
    console.log(file, path);
    var filesInfo = `<li>
                        Name: ${file.name}</br> 
                        Size: ${file.size} bytes</br> 
                        Type: ${file.type}</br> 
                        Modified Date: ${file.lastModifiedDate}
                      </li>`;
    ul.innerHTML += `${filesInfo}`;
  };

  var iterateFilesAndDirs = function(filesAndDirs, path) {
    for (var i = 0; i < filesAndDirs.length; i++) {
      if (typeof filesAndDirs[i].getFilesAndDirectories === 'function') {
        var path = filesAndDirs[i].path;

        // this recursion enables deep traversal of directories
        filesAndDirs[i].getFilesAndDirectories()
          .then(function(subFilesAndDirs) {
            // iterate through files and directories in sub-directory
            iterateFilesAndDirs(subFilesAndDirs, path);
          });
      } else {
        uploadFile(filesAndDirs[i], path);
      }
    }
  };
  if ("getFilesAndDirectories" in event.target) {
    event.target.getFilesAndDirectories()
      .then(function(filesAndDirs) {
        // if directory
        var dir = filesAndDirs;
        if (dir[0] && dir[0].constructor.name === "Directory") {
          
          console.log(dir);
          var directoryInfo = `<li>
                        Directory Name: ${dir[0].name}</br> 
                        Path: ${dir[0].path}
                      </li>`;
          ul.innerHTML += `${directoryInfo}`;
          alert("isDirectory:true");
        }
        iterateFilesAndDirs(dir, "/");
      })

  } else {
    // do webkit stuff
  }
}

dropArea.addEventListener("dragover", dragHandler);
dropArea.addEventListener("change", filesDroped);

input[type="file"] {
  width: 98%;
  height: 180px;
}

label[for="file"] {
    width: 98%;
  height: 180px;
}

.area {
  display:block;
  border: 5px dotted #ccc;
  text-align: center;
}

.area:after {
  display: block;
  border:none;
  white-space: pre;
  /*content: "Drop your files here!\aOr click to select files";*/
  position: relative;
  left: 0%;
  top: -75px;
  text-align:center;
}

.drag {
  border: 5px dotted green;
  background-color: yellow;
}

#result ul {
  list-style: none;
  margin-top: 20px;
}

#result ul li {
  border-bottom: 1px solid #ccc;
  margin-bottom: 10px;
}

<label id="dropArea" class="area">
  <input id="file" type="file" allowdirs directory webkitdirectory/>
</label>
<output id="result">
  <ul></ul>
</output>