Convert array of objects, to object - mongodb

Question

I have a mongo db record like this
items: [
0: {
key: name,
value: y
},
1: {
key: module,
value: z
}
]
And per record my expected output is this
{
name : y,
module : z
}
What is the best mongo db aggregation i should apply to achieve this. I have tried few ways but i am unable to produce output.
We can't use unwind otherwise it will break the relationship between name and module.

Answer 1

Query
the items array is almost ready to become document {}
$map to rename key->k and value->v (those are the field names mongo needs)
$arrayToObject to make the items [] => {}
and then merge items document with the root document
and project the items {} (we don't need it anymore the fields are part of the root document now)
*you can combine the 2 $set in 1 stage, i wrote it in 2 to be simpler
Test code here
aggregate(
[{"$set":
{"items":
{"$map":
{"input": "$items", "in": {"k": "$$this.key", "v": "$$this.value"}}}}},
{"$set": {"items": {"$arrayToObject": ["$items"]}}},
{"$replaceRoot": {"newRoot": {"$mergeObjects": ["$items", "$$ROOT"]}}},
{"$project": {"items": 0}}])

Answer 2

aggregate(
[{
$project: {
items: {
$map: {
input: "$items",
"in": {
"k": "$$this.key",
"v": "$$this.value"
}
}
}
}
}, {
$project: {
items: {
$arrayToObject: "$items"
}
}
}])
Test Code