There is an error in the example
```
clone = clone.crop((clone.bitmap.width: square) / 2, (clone.bitmap.height: square) / 2, square, square);
```

Must use modulus operator.
```
clone = clone.crop((clone.bitmap.width % square) / 2, (clone.bitmap.height % square) / 2, square, square);
```

Step 4 — Creating the Multer Storage Engine

Step 5 — Implementing the `POST /upload` Route

Step 5 — Implementing the POST /upload Route

In this tutorial, we will see how to upload a photo to an Express app and manipulate it (resize, crop, greyscale, etc) before writing it to storage.