// z Post.js
postSchema.virtual("comments", {
  ref: "Comment",
  localField: "_id",
  foreignField: "author"
});

//Comment.js
const mongoose = require("mongoose");

const commentSchema = mongoose.Schema(
  {
    commentedPostId: {
      type: mongoose.Schema.Types.ObjectId,
      ref: "Post",
      required: true
    },
    image: {
      type: Buffer
    },
    author: {
      type: mongoose.Schema.Types.ObjectId,
      ref: "User",
      required: true
    },
    body: {
      type: String
    }
  },
  {
    timestamps: true
  }
);

const Comment = mongoose.model("Comment", commentSchema);

module.exports = Comment;

// z kontrolera post.js
const { id } = req.params;
    const post = await Post.findById(id);
    await post.populate("comments").execPopulate();

    res.status(200).send({
      post,
      comments: post.comments
    });