How to change this response to simple array? - node.js

Question

{
"success": true,
"message": "Result",
"data": [
{
"Here": [
{
"_id": "5ee97ee7f25d1c1482717bdf",
"email": "test1#test.io",
"profileImages": [],
"username": "test1",
"birthday": "2020-06-11T10:11:32.000Z",
"phoneNumber": "[phone]",
"location": "Test Location",
"firstName": "test1",
"lastName": "test1",
}
]
},
{
"Here": [
{
"_id": "5ee97ef2f25d1c1482717be1",
"email": "test2#test.io",
"profileImages": [],
"username": "test2",
"birthday": "2020-06-11T10:11:32.000Z",
"phoneNumber": "[phone]",
"location": "Test Location"
}
]
}
],
}
What I am expecting is this
{
"success": true,
"message": "Result",
data: [
{
"_id": "5ee97ee7f25d1c1482717bdf",
"email": "test1#test.io",
"profileImages": [],
"username": "test1",
"birthday": "2020-06-11T10:11:32.000Z",
"phoneNumber": "[phone]",
"location": "Test Location",
"firstName": "test1",
"lastName": "test1"},
{
"_id": "5ee97ef2f25d1c1482717be1",
"email": "test2#test.io",
"profileImages": [],
"username": "test2",
"birthday": "2020-06-11T10:11:32.000Z",
"phoneNumber": "[phone]",
"location": "Test Location"
}
]
}
Query I am using is for this response is below using aggregation in mongodb, lookup and project which is leading me to the some undesired response
db.collections.aggregate( [
{
$lookup: {
from: 'users',
as: 'Here',
let: {
whoDid: '$whoDid'
},
pipeline: [
{
"$match": { "$expr": { "$eq": ["$_id", "$$whoDid"] } }
},
{
$project: {
_id: 1,
email: 1,
profileImages: 1,
username: 1,
birthday: 1,
phoneNumber: 1,
firstName: 1,
lastName: 1,
fullName: 1,
// age: {$year: "$birthday"}
age: {
$divide: [{ $subtract: [new Date(), "$birthday"] },
(31558464000)]
}
}
}
],
}
},
{
$project:{
Here:1,
_id:0
}
} ,
])
who did table is one of the collection I have where I have stored the user Id and later I am populating the data using lookup
{
"_id" : ObjectId("5ee988eb1aac0022e15dbb7b"),
"whoDid" : ObjectId("5ee97ef2f25d1c1482717be1"),
"toWhomDid" : ObjectId("5ee97ec0f25d1c1482717bdd"),
"modified_at" : ISODate("2020-06-17T03:07:23.217Z"),
"created_at" : ISODate("2020-06-17T03:07:23.217Z"),
"__v" : 0
}
{
"_id" : ObjectId("5ee988eb1aac0022e15dbb7c"),
"whoDid" : ObjectId("5ee97ec0f25d1c1482717bdd"),
"toWhomDid" : ObjectId("5ee97ef2f25d1c1482717be1"),
"modified_at" : ISODate("2020-06-17T03:07:23.220Z"),
"created_at" : ISODate("2020-06-17T03:07:23.220Z"),
"__v" : 0
}
Can anyone suggest me any better option so that I can get a desired respose?

Answer 1

It is possible to use reduce method:
obj.data = obj.data.reduce((a, c) => {
a.push(...c.Here);
return a;
}, [])
An example:
let obj = {
"success": true,
"message": "Result",
"data": [ {
"Here": [ {
"_id": "5ee97ee7f25d1c1482717bdf", "email": "test1#test.io",
"profileImages": [], "username": "test1",
"birthday": "2020-06-11T10:11:32.000Z", "phoneNumber": "[phone]", "location": "Test Location",
"firstName": "test1", "lastName": "test1",
}
]
},
{
"Here": [ {
"_id": "5ee97ef2f25d1c1482717be1",
"email": "test2#test.io",
"profileImages": [],
"username": "test2",
"birthday": "2020-06-11T10:11:32.000Z",
"phoneNumber": "[phone]",
"location": "Test Location"
}
]
}
]
};
obj.data = obj.data.reduce((a, c) => {
a.push(...c.Here);
return a;
}, [])
console.log(obj);

Answer 2

Add these extra steps into your aggregation pipeline:
{
$unwind: "$Here"
},
{
$replaceWith: "$Here"
}
MongoPlayground
Note: You can replace $project: { _id: 1, email: 1, ... to this:
{
$addFields:{
age: {
$divide: [{ $subtract: [new Date(), "$birthday"] },(31558464000)]
}
}
}