Sharp image rotation works only once

Question

I've made a function that rotates images 90 degrees on an Express server in Node.js. It works the first time it is called, but not the 2nd time. If i restart the server, then it will work one more time again, so if I restart the server 3 times then I could rotate the image all the way around.

The Product.findById is a mongoose query to find the image name for the image id specified from the request from the frontend.

In both the first and second try the console.log on line 7 returns the correct plant path/name, and no error is thrown. The response status is 200 "image rotated", both times aswell

router.patch("/rotate/:image", (req, res, next) => {
  let image = ""
  Product.findById(req.params.image)
  .exec()
  .then(result => {
    image = './uploads/resized/'+result.image
    console.log("image", image)

    sharp(image)
    .rotate(90)
    .withMetadata()
    .toBuffer(function(err, buffer) {
      if(err) throw err
      fs.writeFile(image, buffer, function() {
        res.status(200).json("image rotated")
      });
    })
  })
  .catch(err => {res.status(400).json("invalid img id")
    console.log(err)})
  })

Expected output is image rotated 90 degrees on every http request, but the actual output is only image rotated 90 degrees on the first http request.

Answer 1

Try disabling cache writing following line after importing sharp module:

sharp.cache(false);