going full circle 0

app.js

app.post('/comments', (req, res, next) => {
  try {
    const { userId, postId } = req.body;

    const comment = db.createCommentSync(req.body);

    const post = db.getPostSync(postId);
    db.updatePostSync(postId, { comments: post.comments + 1 });

    const user = db.getUserSync(userId);
    db.updateUserSync(userId, { lastComment: comment.id });

    res.json(comment);
  } catch (error) {
    next(error);
  }
});