const reader = fs.createReadStream(file.path);  // 创建可读流


const upStream = fs.createWriteStream(resultPath);      // 创建可写流
reader.pipe(upStream);


upStream.on('finish',()=>{
    console.info(' upStream finish!!')

});

upStream.on('close',()=>{
    console.info(' upStream close!!')

});
reader.on('close',()=>{
    console.info(' reader close!!')

});
reader.on('end',()=>{
    console.info(' reader end!!')

});

输出:// reader end!!
// upStream finish!!
// reader close!!
// upStream close!!