Firebase 云功能错误：“在将标头发送到客户端后无法设置标头”

Posted 2023-03-25

【中文标题】Firebase 云功能错误：“在将标头发送到客户端后无法设置标头”

【英文标题】：Firebase Cloud Function Error: "Cannot set headers after they are sent to the client"

【发布时间】：2021-11-21 10:43:37

【问题描述】：

总的来说，我是 firebase 云功能和 NodeJS 的新手。我正在尝试使用 Cloudinary 的 NodeJS SDK 重命名图像，如下所示：

https://cloudinary.com/documentation/image_upload_api_reference#rename_method

我正在使用 Firebase Cloud Function 来处理后端，但在运行 https 函数时出现以下服务器日志错误：

>  node:_http_outgoing:579
>      throw new ERR_HTTP_HEADERS_SENT('set');
>      ^
> 
>  Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client
>      at new NodeError (node:internal/errors:329:5)
>      at ServerResponse.setHeader (node:_http_outgoing:579:11)
>      at ServerResponse.header (C:\Users\XXX\AppData\Roaming\npm\node_modules\firebase-tools\node_modules\express\lib\response.js:771:10)
>      at ServerResponse.json (C:\Users\XXX\AppData\Roaming\npm\node_modules\firebase-tools\node_modules\express\lib\response.js:264:10)
>      at ServerResponse.send (C:\Users\XXX\AppData\Roaming\npm\node_modules\firebase-tools\node_modules\express\lib\response.js:158:21)
>      at C:\Users\XXX\Desktop\work\XXX\functions\build\cloudinary\rename.js:37:27
>      at C:\Users\nXXX\Desktop\work\Xxxx\functions\node_modules\cloudinary\lib\utils\index.js:1239:14
>      at IncomingMessage.<anonymous> (C:\Users\XXX\Desktop\work\xxx\functions\node_modules\cloudinary\lib\uploader.js:505:9)
>      at IncomingMessage.emit (node:events:381:22)
>      at endReadableNT (node:internal/streams/readable:1307:12) 
>    code: 'ERR_HTTP_HEADERS_SENT'
>  

我的云函数是functions/src/cloudinary/rename.js:

import cloudinary from 'cloudinary'
import * as functions from 'firebase-functions'

const cors = require('cors')( origin: true ) // Automatically allow cross-origin requests for browser fetch

cloudinary.config(
  cloud_name: 'removed',
  api_key: 'removed',
  api_secret: 'removed'
)

export const rename = functions.https.onRequest((req, res) => 
  return cors(req, res, () => 
    try 
      cloudinary.v2.uploader.rename(
        'aircraft_hzwme2',
        'updated_name',
        (error, result) => 
          if (error) 
            res.status(500).send(error)
           else 
            res.send(result)
          
        
      )
      return res.send('hi from rename function')
     catch (error) 
      return res.status(500).send('There was an error in rename function')
    
  ) // end cors wrapper
)

有人知道我做错了什么导致这个错误吗？

【参考方案1】：

我更喜欢在返回发回响应时添加return，因此此后不会执行任何代码（除非您的用例需要），从而防止任何额外的尝试发送响应。在这种情况下，您在 if-else 块之后还有一个额外的 res.send() 语句。尝试像这样重构：

try 
  cloudinary.v2.uploader.rename(
    'aircraft_hzwme2',
    'updated_name',
    (error, result) => 
      if (error) 
        return  res.status(500).send(error) // <-- add return
       else 
        return res.send(result) // <-- add return
      
    )
    // Remove this
    // return res.send('hi from rename function')
 catch (error) 
  return res.status(500).send('There was an error in rename function')