Which method would be more appropriate here POST or PATCH? - node.js

Question

Let's say I have a db collection with users and I want to ADD an object to an array inside one document.
It was like this:
{
_id: "636e8e1dd710eed71565741c",
username: "test",
password: "$2b$10$/s9.kRYSax380Xrxf3xyVO9Z6Otc/WVx5kBSLKfu43/wYP.TSnzvW",
tasks: [{name: task1, status: "finished"}]
}
And I am going to make it look like this:
{
_id: "636e8e1dd710eed71565741c",
username: "test",
password: "$2b$10$/s9.kRYSax380Xrxf3xyVO9Z6Otc/WVx5kBSLKfu43/wYP.TSnzvW",
tasks: [{name: task1, status: "finished"}, {name: task2, status: "unfinished"}]
}
So which method would be more appropriate here since I'm adding a new object to an embedded array and not updating one which already exists? Thank you.

Answer 1

The choice between POST and PATCH depends on the path of the URL. If the path contains the _id, I'd prefer
POST /collection/636e8e1dd710eed71565741c/tasks
Content-Type: application/json
{"name": "task2", "status": "unfinished"}
However, if the _id is part of the payload, I'd prefer
PATCH /collection
Content-Type: application/json
{"_id": "636e8e1dd710eed71565741c",
"tasks#add": [{"name": "task2", "status": "unfinished"}]}
But this payload format relies on "naming conventions":
The _id serves to identify the entry to be patched.
The suffix #add means that the tasks are added to the existing array.
"tasks#change": [{"name": "task1", "status": "archived"}] would instead update the existing task.
If the server knows that each task is identified by its name, the suffixes would not be necessary:
PATCH /collection
Content-Type: application/json
{"_id": "636e8e1dd710eed71565741c",
"tasks": [{"name": "task1", "status": "archived"},
{"name": "task2", "status": "unfinished"}]}
updates the existing task and adds a new one. Or even
PATCH /collection/636e8e1dd710eed71565741c/tasks
Content-Type: application/json
[{"name": "task1", "status": "archived"},
{"name": "task2", "status": "unfinished"}]
I hope these examples help you find a suitable pattern.