How to use populate on saving new data on mongoose

Question

Hello their I am trying to populate postedBy field on creating a new comment. When i create a comment i save it on mongodb and also I save comment._id on my feature model (as objectId) then i am sending res.json(comment) Can i populate before sending json response? I also tried but nothing happened My code-

exports.createComment = async (req, res) => {
  console.log("run?");
  const { featureId } = req.params;
  const { content } = req.body;
  const postedBy = req.auth._id;
  if (!content) {
    return res
      .status(400)
      .send({ error: "Please provide a content with your comment." });
  }
  const comment = new Comment({
    content,
    postedBy,
  });
  await comment.save();
  await comment.populate("postedBy", "_id username");
  Feature.findByIdAndUpdate(
    featureId,
    { $push: { comments: comment._id } },
    { new: true }
  ).exec((err, result) => {
    if (err) {
      return res.json({
        error: errorHandler(err),
      });
    }
  });
  return res.json(comment);
};```

Answer 1

exports.createComment = async (req, res) => {
console.log("run?");
const { featureId } = req.params;
const { content } = req.body;
const postedBy = req.auth._id;
if (!content) {
  return res
    .status(400)
    .send({ error: "Please provide a content with your comment." });
}
const comment = new Comment({
  content,
  postedBy,
});
await comment.save();

// One of the ways that I use.
let populatedData= await Comment.findById(comment._id).populate("postedBy", "_id username");
console.log(populatedData)

Feature.findByIdAndUpdate(
  featureId,
  { $push: { comments: comment._id } },
  { new: true }
).exec((err, result) => {
  if (err) {
    return res.json({
      error: errorHandler(err),
    });
  }
});
return res.json(comment);
};