Support for JSON Merge Patch (RFC 7386)

[Tiberriver256]

Is your feature request related to a problem? Please describe.

Implementing JSON Merge Patch manually can be quite tricky but provides a simpler experience for API consumers.

Describe the solution you'd like

Currently there is built-in support for JSON Patch (RFC 6902) via JsonPatchDocument. Would love to also see an implementation of RFC 7386.

So no one has to wade through an RFC...

Given the following JSON representation:

{
  "name": "Joe",
  "email": "joe@example.com",
  "physicalAttributes": { "weight": 75, "height": 175 },
  "favoriteColors": ["blue", "red"]
}

These two will produce equivalent modifications:

JSON Patch

[
   { "op": "remove", "path": "/email" },
   { "op": "add", "path": "/favoriteColors/-", "value": "black" }
]

JSON Merge Patch

{
  "email": null,
  "favoriteColors": ["blue", "red", "black"]
}

Additional context

OData has an implementation of this spec via Delta but it was not designed to work with formatters other than OData.

Here are a couple of open-source implementations:
https://www.strathweb.com/2013/01/easy-asp-net-web-api-resource-updates-with-delta/
https://github.com/Morcatko/Morcatko.AspNetCore.JsonMergePatch

We've moved this issue to the Backlog milestone. This means that it is not going to be worked on for the coming release. We will reassess the backlog following the current release and consider this item at that time. To learn more about our issue management process and to have better expectation regarding different types of issues you can read our Triage Process.

[mitsha-microsoft]

Hi,
Our service uses PATCH primarily for a huge set of our APIs and having something built-in that handles RFC 7386 will help us greatly (otherwise we will need to roll out our own implementation or use a third party OSS package).

[desjoerd]

@mikekistler I totally agree that this is the more friendly patch method like you mentioned in the .NET 10 Preview4 unboxed!.

I currently use my "own" wrapper value to be able to do this https://github.com/desjoerd/OptionalValues. But having native support for this would be awesome.

I also have an horrible implementation which runs on json level... https://github.com/desjoerd/toolbox/tree/main/dotnet/Toolbox/JsonMerge

Is adding this something which is open for help?

[SemaphoreSlim1]

DotNext already has this implemented, tested, and ready to go - and has the benefit of being "official" Microsoft code.
https://dotnet.github.io/dotNext/features/core/optional.html