How to update the field date when findOneAndUpdate

[ZeusZoe]

Hi, I've this schema and route:

const date=(v)=>{
    console.log(typeof v,v);
    v=new Date();
    return v;
};

const testSchema=new Schema({
    _id:Number,
    name:String,
    createdAt:{type:Date,default:Date.now,immutable:true},
    updatedAt:{type:Date,default:Date.now,set:date}
},{versionKey:false});

router.put("/",async(req,res)=>{
    const c=req.body;
    const d=await testModel.findOneAndUpdate({_id:c._id,updatedAt:c.updatedAt},c);
    res.json(d);
});

I noted that the set function (date) is call two onces (why) and the record is not updated when the filter contain 'updatedAt' field too.

I use this data for verify:

{
	"_id" : 1,
	"name" : "John Doe",
	"createdAt" : "2024-01-21T08:51:13.826+01:00",
	"updatedAt" : "2024-01-21T10:11:20.422+01:00"
}

If I remove the setter function from schema, it work fine.

[vkarpov15]

The setter is called twice because Mongoose calls setters on filter properties and update properties. So the setter runs once for updatedAt in filter and once for updatedAt in update. So updatedAt in the filter is updated to the current date, and you get an unexpected query.

In general, I would recommend you use defaults if you're looking to set a default value, not setters. You should also take a look at Mongoose's timestamps docs so you don't have to implement timestamps yourself.

[ZeusZoe]

Thanks.
Timestamps with findOneAndReplace is not best solution, I believe.
I use findOneAndReplace because my schema include more sub-schema that could be null or default.
I not do want serialize null or empty fields when I need to update the record