Add Aggregate field in MongoDB pipeline depending on all elements of an array - mongodb

Question

Given the following documents in a collection:
[{
"_id": {
"$oid": "63f06283b80a395adf27780d"
},
"suppliers": [
{
"name": "S1",
"duesPaid": true
},
{
"name": "S2",
"duesPaid": true
}
]
},{
"_id": {
"$oid": "63f06283b80a395adf27780e"
},
"suppliers": [
{
"name": "S1",
"duesPaid": true
},
{
"name": "S2",
"duesPaid": false
}
]
}]
I would like to create an aggregateField in each document that does the following: If the suppliers array has at least 1 element and every element in that has the duesPaid field == true, then add a field to the document suppliersPaid = true. Otherwise add suppliersPaid = false. The resulting documents from the pipeline should look like this:
[{
"_id": {
"$oid": "63f06283b80a395adf27780d"
},
"suppliers": [
{
"name": "S1",
"duesPaid": true
},
{
"name": "S2",
"duesPaid": true
}
],
"suppliersPaid": true,
},{
"_id": {
"$oid": "63f06283b80a395adf27780e"
},
"suppliers": [
{
"name": "S1",
"duesPaid": true
},
{
"name": "S2",
"duesPaid": false
}
],
"suppliersPaid": false,
}]
I have tried the following pipeline:
[{$addFields: {
suppliersPaid: {
$and: [
{ $gte: [{ $size: "$suppliers" }, 1] },
{
suppliers: {
$not: {
$elemMatch: { duesPaid: false },
},
},
},
],
},
}}]
and I get the following error: Invalid $addFields :: caused by :: Unrecognized expression '$elemMatch'
I've tried to eliminate the reliance on $elemMatch per the docs https://www.mongodb.com/docs/manual/reference/operator/query/elemMatch/#single-query-condition as such:
[{$addFields: {
suppliersPaid: {
$and: [
{ $gte: [{ $size: "$suppliers" }, 1] },
{
suppliers: {
$not: {
duesPaid: false
},
},
},
],
},
}}]
But this yields the incorrect result of setting suppliersPaid to true for both documents, which is incorrect.
Note: I would like to avoid using any sort of JS in this code i.e. no $where operators.

Answer 1

For the second condition:
$eq - Compare the result from 1.1 to return an empty array.
1.1. $filter - Filter the documents from suppliers containing { duesPaid: false }.
db.collection.aggregate([
{
$addFields: {
suppliersPaid: {
$and: [
{
$gte: [
{
$size: "$suppliers"
},
1
]
},
{
$eq: [
{
$filter: {
input: "$suppliers",
cond: {
$eq: [
"$$this.duesPaid",
false
]
}
}
},
[]
]
}
]
}
}
}
])
Demo # Mongo Playground