Count from mongo of the same query with limit 1 (Node.js) - mongodb

Question

My query is :
event.find({
id:{$get:id},
num:"5"
}).limit(1)
but i also do the same query and get count result (from the same query)
so 1 result is the last one with limit 1 and second is the count without the limit
how do i do that in MongoDB ?
one option i was think about is do the same query but without limit , for example, get 2000 results and count in node.js code.
my node code:
result = await this.collection.find({
'val':obj.val,
'id' : {$lt: id}
}).sort({id:-1}).limit(1).project({_id:0})
let count = await result.count()
but count always return 1 (because the count should ignore the id option)
is it possible?
example:
request is name=yy and id =3
1- { id :3 , name:yy },
2 - {id : 2 , name:yy}
another example
result will be : row 2 (3 greater than 2) . with count = 2
1- { id :3 , name:yy },
2 - {id : 2 , name:xx}
result will be : [] with count = 1 . (the same query without id < id)

Answer 1

You can try below aggregation using $facet
result = await this.collection.aggregate([
{ "$facet": {
"count": [
{ "$match": { "id": { "$lte": id }}},
{ "$count": "count" }
],
"data": [
{ "$match": { "val": obj.val, "id" : id }},
{ "$sort": { "id": -1 }},
{ "$limit": 1 },
{ "$project": { "_id": 0 }}
]
}}
])
result = result[0].data
const count = result[0].count