# 进度
SuperAgent 会在上传和下载大文件时触发 progress 事件。
request.post(url)
.attach('field_name', file)
.on('progress', event => {
/* the event is:
{
direction: "upload" or "download"
percent: 0 to 100 // may be missing if file size is unknown
total: // total file size, may be missing
loaded: // bytes downloaded or uploaded so far
} */
})
.then()