title: Unable to post to json data
body: <p>I'm getting this error while trying to post image together with json data.
  Error: Value for argument "data" is not a valid Firestore document. Cannot use "undefined" as a Firestore value (found in field "price")enter image description here</p>
  
  <pre><code>   let imageUrl;
  
     const BusBoy = require('busboy');
     const path = require('path');
     const os = require('os');
     const fs = require('fs');
  
     const busboy = new BusBoy({ headers: req.headers });
  
     let imageToBeUploaded = {};
     let imageFileName;
  
     busboy.on('file', (fieldname, file, filename, encoding, mimetype) =&gt; {
       console.log(fieldname, file, filename, encoding, mimetype);
       if (mimetype !== 'image/jpeg' &amp;&amp; mimetype !== 'image/png') {
         return res.status(400).json({ error: 'Wrong file type submitted' });
       }
       // my.image.png =&gt; ['my', 'image', 'png']
       const imageExtension = filename.split('.')[filename.split('.').length - 1];
       // 32756238461724837.png
       imageFileName = `${Math.round(
         Math.random() * 1000000000000
       ).toString()}.${imageExtension}`;
       const filepath = path.join(os.tmpdir(), imageFileName);
       imageToBeUploaded = { filepath, mimetype };
       file.pipe(fs.createWriteStream(filepath));
     });
     busboy.on('finish', () =&gt; {
       admin
         .storage()
         .bucket(`${config.storageBucket}`)
         .upload(imageToBeUploaded.filepath, {
           resumable: false,
           metadata: {
             metadata: {
               contentType: imageToBeUploaded.mimetype
             }
           }
         })
         .then(() =&gt; {
           imageUrl = `https://firebasestorage.googleapis.com/v0/b/${
             config.storageBucket
           }/o/${imageFileName}?alt=media`;
           const newProduct = {
               description: req.body.description,
               price: req.body.price,
               title: req.body.title,
               createdAt: new Date().toISOString(),
               likeCount:0,
               reviewCount:0,
               orderCount: 0,
               storeName: req.user.userName,
               sellerImage: req.user.imageUrl,
               imageUrl: imageUrl,
           };
  
           db .collection('products')
               .add(newProduct)
               .then(doc =&gt; {
                   const resProduct = newProduct;
                   resProduct.productId = doc.id;
                   res.json(resProduct);
               })
  
         })
         .then(() =&gt; {
           return res.json({ message: 'product uploaded successfully' });
         })
         .catch((err) =&gt; {
           console.error(err);
           return res.status(500).json({ error: 'something went wrong' });
         });
     });
     busboy.end(req.rawBody);
  };
  </code></pre>
  
  <p>Is it possible to post file and json data together in postman?</p>