Mongodb – multer-gridfs error " TypeError: Cannot read properties of undefined (reading '_id') "

I’m working on creating a WhatsApp clone and implementing a file sharing feature. Everything was going smoothly until I encountered this error that’s causing my backend to crash. The strange thing is, I can see the file in MongoDB, but the error persists. I’m hoping someone can help me troubleshoot this issue.

Here’s a summary of what’s happening:

I have a file sharing feature in my WhatsApp clone app.
When a user tries to share a file, it’s saved to MongoDB.
I can confirm that the file exists in the MongoDB database.
However, the backend crashes with an error that I can’t seem to resolve.
I’m not sure where to begin troubleshooting this issue. Can anyone provide insights on what might be causing this problem? Is there a common mistake I might be making when dealing with file sharing in a MongoDB database?

i cant post all my code here my question will be too long [here is my github link][1]

api.js

export const uploadFile = async (data) => {
    try {
        return await axios.post(`${url}/file/upload`, data);
    } catch (error) {
        console.log('Error while calling uploadfile API ', error);
    }
}

controller

const url = 'http://localhost:8000';
export const uploadFile = async(request, response)=>{
    if(!request.file){
        return response.status(404).json("file not found")
    }
    const imageUrl = `${url}/file/${request.file.filename}`;
    return response.status(200).json(imageUrl);
}

route.js

//Route for file upload
route.post('/file/upload', upload.single("file"), uploadFile);

error

C:UsersuserOneDriveDocumentswebdevwhatsapp clone selfservernode_modulesmulter-gridfs-storagelibgridfs.js:306
                        id: f._id,
                              ^

TypeError: Cannot read properties of undefined (reading '_id')       
    at GridFSBucketWriteStream.emitFile (C:UsersSiddhOneDriveDocumentswebdevwhatsapp clone selfservernode_modulesmulter-gridfs-storagelibgridfs.js:306:31)
    at GridFSBucketWriteStream.emit (node:events:526:35)
    at finish (node:internal/streams/writable:807:10)
    at process.processTicksAndRejections (node:internal/process/task_queues:82:21)

Node.js v20.9.0
[nodemon] app crashed - waiting for file changes before starting...