How to mongo aggregate with lookup and geoIntersects - mongodb

Question

I want to lookup which users are in a specific area, so, if i have these objects on users collection:
{
"_id" : ObjectId("6197a78308591026b742cbc7"),
"longitude" : -8.88180350512795,
"latitude" : 38.5628716186268
}
/* 2 */
{
"_id" : ObjectId("6199798916317b0c2dcab874"),
"longitude" : -9.15904389999993,
"latitude" : 38.7235087
}
/* 3 */
{
"_id" : ObjectId("6199798916317b0c2dcab874"),
"longitude" : -8.6923178,
"latitude" : 41.1846394
}
And i have other collection deliveryareas with this object:
{
"_id" : ObjectId("6197ebf6fdbd8f6b06c97c57"),
"area" : {
"type" : "Polygon",
"coordinates" : [
[
[
-9.0556241,
38.4989521
],
[
-9.0551516,
38.4964531
],
[
-9.0522346,
38.4950589
],
[
-9.0526648,
38.4940872
]
]
],
"_id" : ObjectId("6197ebf6fdbd8f6b06c97c58")
}
}
Making this query:
db.getCollection('users').aggregate([
{
$lookup: {
from: 'deliveryareas',
let: { longitude: '$longitude', latitude: '$latitude' },
pipeline: [
{ $match: {
area: {
$geoIntersects: {
$geometry: {
type: 'Point',
coordinates: [ '$$longitude', '$$latitude' ],
},
},
}
} },
],
as: 'inRegion',
},
},
])
if i run the query directly in the deliveryareas collection it works, but over the pipeline on lookup don't work and it's giving the error "Point must only contain numeric elements", can anyone tell me why?

Answer 1

Just one more thing, if i run first this:
db.getCollection('users').aggregate([
{ $unwind: '$addresses' },
{ $project: { coordinates: [ '$addresses.region.longitude', '$addresses.region.latitude' ] } },
])
I have this results:
/* 1 */
{
"_id" : ObjectId("6197a78308591026b742cbc7"),
"coordinates" : [
-8.88180350512795,
38.5628716186268
]
}
/* 2 */
{
"_id" : ObjectId("6199798916317b0c2dcab874"),
"coordinates" : [
-9.15904389999993,
38.7235087
]
}
/* 3 */
{
"_id" : ObjectId("6199798916317b0c2dcab874"),
"coordinates" : [
-8.6923178,
41.1846394
]
}
Then if i add the lookup:
db.getCollection('users').aggregate([
{ $unwind: '$addresses' },
{ $project: { coordinates: [ '$addresses.region.longitude', '$addresses.region.latitude' ] } },
{
$lookup: {
from: 'deliveryareas',
let: { userCoordinates: '$coordinates' },
pipeline: [
{ $match: {
area: {
$geoIntersects: {
$geometry: {
type: 'Point',
coordinates: '$$userCoordinates',
},
},
}
} },
],
as: 'inRegion',
},
},
])
i have the error: Point must be an array or object
but if i replace the variable $$userCoordinates by a fixed value, for example [ -8.88180350512795, 38.5628716186268 ] (that i have on the users) the query run with success.