Check if object present in array, if present set status true in nodejs mongoose

Question

I have a posts model in mongoose as follows:

let PostSchema = new mongoose.Schema({
   message: {
    type: String,
    default: 'NA'
   },
   likeCount: {
    type: Number,
    default: 0
   },
   likes: [{
    userId: {
        type: mongoose.Schema.Types.ObjectId,
        ref: 'User'
    }
   }]
});

all the likes users will be stored in likes array. Now I'm using following request

/get_posts/:userID

where userId is ID of user, now I want to write a query to get result like following:

{
   "posts": [
    {
        "_id": "5ae1975acf8db214e4a920cf",
        "message": "test message",
        "likeCount": 1,
        "isLiked": true
    },
    {
        "_id": "5ae2cf410cc9401ce4cd0bf6",
        "message": "test message 1",
        "likeCount": 2,
        "isLiked": false
    }
}

Here "isLiked" is true if the user ID present in likes array. Please help me to write query