云函数调用 cloude.uploadFile 上传小程序码 buffer 失败？

成功获取了小程序码，把 buffer 传给 云函数 里面的 cloud.uploadFile, 报错了

（已经自查了参数，都是对的）

Error: errCode: -404011 cloud function execution error | errMsg: cloud.callFunction:fail requestID 2ec49c4a-4f04-11eb-b537-52540094fc60, cloud function service error code -504002, error message Error: errCode: -1 unknown error | errMsg: uploadFile:fail TypeError: source.on is not a function; at uploadFile api; 

    at returnAsCloudSDKError (:40426/var/user/node_modules/wx-server-sdk/index.js:7814)

    at Object.returnAsFinalCloudSDKError (:40426/var/user/node_modules/wx-server-sdk/index.js:7828)

    at Promise (:40426/var/user/node_modules/wx-server-sdk/index.js:2784)

    at process._tickCallback (:40426/appservice/internal/process/next_tick.js:68); at cloud.callFunction api; 

    at new g (VM608 WAService.js:2)

    at c (VM608 WAService.js:2)

    at I (VM608 WAService.js:2)

    at Function.success (VM608 WAService.js:2)

    at C (VM608 WAService.js:2)

    at VM608 WAService.js:2

    at u (VM608 WAService.js:2)

    at Function.<anonymous> (VM608 WAService.js:2)

    at C (VM608 WAService.js:2)

    at VM608 WAService.js:2