Update or append to a subcollection in mongo - mongodb

Question

I have a collection containing a subcollection. In one request, I would like to update a record in the subcollection or append to it if a match doesn't exist. For a bonus point I would also like this update to be a merge rather than an overwrite.
A crude example:
// Schema
{
subColl: [
{
name: String,
value: Number,
other: Number,
},
];
}
// Existing record
{
_id : 123,
subColl: [
{name: 'John',
value: 10,
other: 20}
]
}
// example
const update = { _id: 123, name: 'John', other: 1000 };
const { _id, name, other } = update;
const doc = await Schema.findById(_id);
const idx = doc.subColl.findIndex(({ name: nameInDoc }) => nameInDoc === name);
if (idx >= 0) {
doc.subColl[idx] = { ...doc.subColl[idx], other };
} else {
doc.subColl.push({ name, other });
}
doc.save();
Currently I can achieve this result by pulling the record, and doing the update/append manually but I am assuming that achieving it with a pure mongo query would be much faster.
I have tried:
Schema.findOneAndUpdate(
{ _id: 123, 'subColl.name': 'John' },
{ $set: { 'subColl.$': [{ name: 'John', other: 1000 }] } }
)
but this won't handle the append behaviour and also doesn't merge the object with the existing record, rather it overwrites it completely.

Answer 1

I am not sure is there any straight way to do this in single query,
Update with aggregation pipeline starting from MongoDB v4.2,
$cond to check name is in subColl array,
true condition, need to merge with existing object, $map to iterate loop, check condition if matches condition then merge new data object with current object using $mergeObjects
false condition, need to concat arrays, current subColl array and new object using $concatArrays
const _id = 123;
const update = { name: 'John', other: 1000 };
Schema.findOneAndUpdate(
{ _id: _id },
[{
$set: {
subColl: {
$cond: [
{ $in: [update.name, "$subColl.name"] },
{
$map: {
input: "$subColl",
in: {
$cond: [
{ $eq: ["$$this.name", update.name] },
{ $mergeObjects: ["$$this", update] },
"$$this"
]
}
}
},
{ $concatArrays: ["$subColl", [update]] }
]
}
}
}]
)
Playground