mongodb: pull element from nested array where date is before now - mongodb

Question

I am having an issue which deemed to be so simple. Given nested documents that have an expires field. One example document:
{
_id: ObjectId(),
stuff: [
{
name: 'egg',
expires: ISODate("2019-07-19T12:52:56.163Z")
},
{
name: 'potato',
expires: ISODate("2019-07-19T12:52:56.163Z")
}
]
}
I thought I could use a query like that:
db.collection.update({"_id": ObjectId("578411d30af77c226c52b940")}, {
"$pull": {
"stuff.expires": { "$lt": ISODate() }
}
});
possibly being able to apply that to multiple documents at once, but even when trying to update a single document I run into that error:
Cannot use the part (expires) of (stuff.expires) to traverse the element
I tried a ton of modifications, but I was not able to find a way to make this work or a similar example (which seems to be quite odd when searching for mongodb stuff).
If there is no way to update multiple documents at once, I would be happy if there would be a way to remove all expired items from a single document in an atomic query. The query does not need to work with older mongodb versions - latest version is fine.

Answer 1

I think you can achieve what you want using this query:
db.collection.update({}, {
$pull: {
stuff: {
expires: {
$lt: ISODate()
}
}
}
}, {
multi: true
})
The above query will target all documents, and will pull every stuff object which expires property is lower than your ISODate()
the multi:true is the option to allow to update multiple documents