node.js – 在Sails js中检查上传的文件扩展名

我们如何在sails js中检查上传的文件扩展名？
我尝试了 skipper和 multer,但没有结果.
有什么建议吗？ 在保存之前,您应该为每个文件使用saveAs选项.

var md5 = require('md5');
module.exports = {

  testUpload:function(req,res){

     // setting allowed file types
     var allowedTypes = ['image/jpeg', 'image/png'];

     // skipper default upload directory .tmphttp://img.558idc.com/uploadfile/
     var allowedDir = "../../assets/images";

    // don not define dirname , use default path
    req.file("uploadFiles").upload({
       saveAs:function(file, cb) {
          var d = new Date();
          var extension = file.filename.split('.').pop();
          // generating unique filename with extension
          var uuid=md5(d.getMilliseconds())+"."+ extension;

          // seperate allowed and disallowed file types
          if(allowedTypes.indexOf(file.headers['content-type']) === -1) {
            // save as disallowed files default upload path
            cb(null,uuid);
          }else{
            // save as allowed files
            cb(null,allowedDir+"/"+uuid);
          }
       }
    },function whenDone(err,files){
       return res.json({
         files:files,
         err:err
        });
      });
    }
 }