MongooseJS: Having a hard time populating a list of comments

I have a schema called Post, and in the Schema, there is a comments attribute.

const mongoose = require("mongoose");
const Schema = mongoose.Schema;

const PostSchema = new Schema({
    user: {
        type: Schema.Types.ObjectId,
        ref: "users",
    },
    text: {
        type: String,
        required: true,
    },
    name: {
        type: String,
    },
    avatar: {
        type: String,
    },
    likes: [
        {
            user: {
                type: Schema.Types.ObjectId,
                ref: "users",
            },
        },
    ],
    comments: [
        {
                type: Schema.Types.ObjectId,
                ref: "comments",
        },
    ],
    date: {
        type: Date,
        default: Date.now,
    },
});

module.exports = Post = mongoose.model("post", PostSchema);

Here is my Comments schema.

const mongoose = require("mongoose");
const Schema = mongoose.Schema;

const CommentSchema = new Schema({
    post: {
        type: Schema.Types.ObjectId,
        ref: "posts",
    },
    user: {
        type: Schema.Types.ObjectId,
        ref: "users",
    },
    text: {
        type: String,
        required: true,
    },
    name: {
        type: String,
    },
    avatar: {
        type: String,
    },
    likes: [
        {
            user: {
                type: Schema.Types.ObjectId,
                ref: "users",
            },
        },
    ],
    replies: [
        {
                type: Schema.Types.ObjectId,
                ref: "comments",
        },
    ],
    date: {
        type: Date,
        default: Date.now,
    },
});
module.exports = Comment = mongoose.model("comment", CommentSchema);

When I print out the data accessed by a post, I get it like below:

{
    "_id": "630a82d564540e7196fe4887",
    "user": "6301a168783647db9f7a37c8",
    "text": "For the police I say ____ you punk, reading my rights and ____ it's all junk",
    "name": "e",
    "avatar": "//www.gravatar.com/avatar/8fd046f9f8f50ab2903fa9fd6c845134?s=200&r=pg&d=mm",
    "comments": [
        "630aa7c425ae8add2b275b53",
        "630a834959110e8e3305b471",
        "630a83200cd98eb07fb5f543"
    ],
    "likes": [],
    "date": "2022-08-27T20:47:17.888Z",
    "__v": 3
}

I have tried to populate the comments shown below but I’m getting an error:

router.post(
    "/commentOnPost/",
    [auth, check("text", "Text is required").not().isEmpty()],
    async (req, res) => {
        const errors = validationResult(req);
        if (!errors.isEmpty()) {
            return res.status(400).json({ errors: errors.array() });
        }
        try {
            const user = await User.findById(req.user.id);
            const post = await Post.findById(req.body.post_id).populate('comments');
            let newComment = Comment({
                post: post.id,
                text: req.body.text,
                name: user.name,
                avatar: user.avatar,
                user: req.user.id,
            });
            await newComment.save();
            post.comments.unshift(newComment);
            await post.save();
            return res.json(await post);
        } catch (err) {
            errorLog(err);
            res.status(500).send("Server error");
        }
    }
);

Sat Aug 27 2022 19:27:22 GMT-0400 (Eastern Daylight Time),  -> MissingSchemaError: Schema hasn't been registered for model "comments".
Use mongoose.model(name, schema)

>Solution :

In your Comment schema, you named model as "comment". But in the Post schema, you referenced it as "comments".

Change your code in Post schema like this:

comments: [{ type: Schema.Types.ObjectId, ref: "comment" }],