How findOneAndUpdate Method works, getting null as a result

Question

What i am trying to create, find a comment based on commentId also finding that particular comment which should not be postedBy currently loggedin user I am trying to create commentVote functionality, loggedIn user cant vote his comment or post. getting null as a result

my voteComment Controller Method -

exports.voteComment = (req, res) => {
  const { commentId } = req.params;
  if (!ObjectId.isValid(commentId)) {
    return res.status(400).send({
      error: "Comment ID not valid",
    });
  }
  console.log(typeof req.auth._id);
  Comment.findOneAndUpdate(
    { commentId, "comment.postedBy": { $ne: req.auth._id } },
    { $push: { votes: req.auth._id } },
    { new: true }
    // { omitUndefined: true }
    // { returnNewDocument: true }
  ).exec((err, result) => {
    if (err) {
      return res.status(400).json({
        error: "Could not vote on that comment",
      });
    }
    console.log(result);
    res.json(result);
    // if (result.nModified) {
    //   console.log("test");
    // }
  });

My Comment Model-

const mongoose = require("mongoose");
const { ObjectId } = mongoose.Schema;

const commentSchema = new mongoose.Schema(
  {
    content: {
      type: String,
      required: true,
      trim: true,
      max: 200,
    },
    postedBy: {
      type: ObjectId,
      ref: "User",
      required: true,
    },
    feature: {
      type: ObjectId,
      ref: "Feature",
      required: true,
    },

    votes: [{ type: ObjectId, ref: "User" }],
    replies: [
      {
        content: {
          type: String,
          required: true,
          trim: true,
          max: 200,
        },
        postedBy: {
          type: ObjectId,
          ref: "User",
        },
        created: {
          type: Date,
          default: Date.now,
        },
        votes: [
          {
            postedBy: {
              type: ObjectId,
              ref: "User",
            },
            created: {
              type: Date,
              default: Date.now,
            },
          },
        ],
      },
    ],

  },
  { timestamps: true }
);

module.exports = mongoose.model("Comment", commentSchema);

I also want to create error handling so that if Comment isn't updated so i can modify it by checking if(comment.nModified) but i dont know how to use .nModified and .ok on response from mongoose

score 0 · Answer 1 · answered Jan 10 '23 at 15:53

Try this:

exports.voteComment = (req, res) => {
  const { commentId } = req.params;
  
  if (!ObjectId.isValid(commentId)) {
    return res.status(400).send({
      error: "Comment ID not valid",
    });
  }
  Comment.findOneAndUpdate(
    { commentId, "comment.postedBy": { $ne: req.auth._id } },
    { $push: { votes: req.auth._id } },
    { new: true }
    // { omitUndefined: true }
    // { returnNewDocument: true }
  ).exec((err, result) => {
    if (err) {
      return res.status(400).json({
        error: "Could not vote on that comment",
      });
    }
    if(result === null) {
      return res.status(400).json({
        error: "You can't vote on your own comment"
      });
    }
    res.json(result);
  });

How findOneAndUpdate Method works, getting null as a result

1 Answers1