Mongoose update validation breaks the update request - node.js

Question

price: {
type: Number,
required: [true, 'A tour must have a price'],
},
priceDiscount: {
type: Number,
validate: function (val) {
return val < this.price;
}
The validation here tests if the discount price is less than the actual price if so it should work with no problems (it works if I am creating a new tour on the update it doesn't)
It just gives back a validation error even if the discount is less than the price ( "price": 997,
"priceDiscount":10)
"status": "FAIL",
"message": {
"errors": {
"priceDiscount": {
"name": "ValidatorError",
"message": "Validator failed for path `priceDiscount` with value `10`",
"properties": {
"message": "Validator failed for path `priceDiscount` with value `10`",
"type": "user defined",
"path": "priceDiscount",
"value": 10
},
"kind": "user defined",
"path": "priceDiscount",
"value": 10
}
},
"_message": "Validation failed",
"name": "ValidationError",
"message": "Validation failed: priceDiscount: Validator failed for path `priceDiscount` with value `10`"
}
I already have my runValidators: true
exports.UpdateTour = async (req, res) => {
try {
const upTour = await Tour.findByIdAndUpdate(req.params.id, req.body, {
new: true,
runValidators: true,
});
res.status(200).json({
status: 'success',
data: {
tour: `UPDATE TOUR #${req.params.id}
${upTour}`,
},
});
} catch (err) {
res.status(400).json({
status: 'FAIL',
message: err,
});
}
};

Answer 1

I found a solution that might not be optimal but it worked. I used a middleware function that checks the condition whenever the findByIdAndUpdate is triggered and it solved the problem.
Mongoose middleware docs where I came up with this idea
code sample:
tourSchema.post(/Update$/, async function (docs, next) {
let tour = await this.model.findOne(this.getQuery());
if (tour.price <= tour.priceDiscount) {
//set the discount price to 0 if the price is lower
tour.set({ priceDiscount: 0 });
tour.save();
next(new Error('The discount price is larger than the price'));
} else {
next();
}
});