const router = express.Router({mergeParams:true});
const wrapAsync = (fn)=>{
    return (req,res,next)=>{
        fn(req,res,next).catch(next);
    }
}
const validateReview = (req,res, next)=>{
    let {error} = reviewSchema.validate(req.body);
    if(error){
        let errMsg = error.details.map((el)=>el.message).join(",");
        throw new ExpressError(400, errMsg);
    }else{
        next();
    }
}
router.post("/", validateReview, wrapAsync(async(req,res)=>{
    let listing = await Listing.findById(req.params.id);
    let newReview = new Review(req.body.review);
    
    listing.reviews.push(newReview);
    
    await newReview.save();
    await listing.save();
    res.redirect(`/listings/${listing._id}`);
}));

This is the child express route to app.js

Listing validation failed: title: Path `title` is required.

now reviews contains only two fields, rating and comment, and has no title, I don’t understand where I can disable the title requirement from. The values in the form is not validating.

When I try to print the listing, req.params.id, req.body, newReview, its all working. There’s something wrong with validation requirement, which says there should be a valid title, but there’s no title field defined in the reviews object.