corka149

Jsonpatch - Pure Elixir implementation of RFC 6902

A JSON patch is a way to define a sequence of manipulating operations on a JavaScript object. The IETF published the RFC 6902 - found here RFC 6902 - JavaScript Object Notation (JSON) Patch. The Kubernetes API is an user of those JSON patches. In my opinion this is the easiest way to change a Kubernetes resource. Unfortunantely no library was available until yet or I did not fount it. This was my motivation to create the JSON patch library.

Get Jsonpatch here jsonpatch | Hex
Read the documentation here Jsonpatch — Jsonpatch v2.3.1
And source GitHub - corka149/jsonpatch: A implementation of RFC 6902 in pure Elixir. · GitHub

In this sense - keep calm and code Elixir
Your Corka/Sebastian

18 comments

#library #json #jsonpatch

18 4570 18

2025-08-11 11:59:34 UTC

First Post!

olafura

There was:

But it doesn’t seem to have been updated in a while according to hex. Also when I used that library at my last company I noticed it wasn’t that fast. So there is defiantly room for improvement.

I’m not sure it’s good to rely on a json encoder/decoder.

Also be careful about lists they are not that clear in json patch standard and can cause of lot of problems.

Post #1

Most Liked

corka149

v1.0.0

I know it exists but never had the time to implement it. I am talking about that patching of lists at top level never worked. This was for me the milestone for v1.0.0. Finally it is fixed. .

Changes:

Allow lists at top level of Jsonpatch.apply_patch
Fix error message when updating a non existing key in list
Performance boost for diffing

Example of new feature:

iex(1)> source = [1, 2, 3, 5, 6]
[1, 2, 3, 5, 6]
iex(2)> destination = [1, 2, 3, 4, 5, 6]
[1, 2, 3, 4, 5, 6]
iex(3)> patch = Jsonpatch.diff source, destination
[
  %Jsonpatch.Operation.Add{path: "/5", value: 6},
  %Jsonpatch.Operation.Replace{path: "/4", value: 5},
  %Jsonpatch.Operation.Replace{path: "/3", value: 4}
]
iex(4)> Jsonpatch.apply_patch! patch, source
[1, 2, 3, 4, 5, 6]

Post #11

corka149

v0.9.3

It has been a since the last update. I worked on testing to eliminate dead code and bugs (of course). Also I tried to make the documentation a little bit prettier.

Jsonpatch — Jsonpatch v2.3.1 |> read_documentation
jsonpatch | Hex |> get_dependency
GitHub - corka149/jsonpatch: A implementation of RFC 6902 in pure Elixir. · GitHub |> browse_code

I am happy about any feedback.

Your Corka/Sebastian

Post #4

corka149

v0.11.0

The whole process for creating patches through Jsonpatch.diff/2 was not perfect. I was encouraged through a github issue to rewrite it with a reduce-loop. This version fixes this. In addition, Jsonpatch.FlatMap was removed because it is not necessary anymore and it was not the focus of this lib.

Changelog:

Removed module Jsonpatch.FlatMap because it is not necessary anymore and not the focus of the lib
Reworked creating diff to create less unnecessary data and for more accurate patches
Fixed adding values to empty lists (thanks @webdeb )

Updated documentation: Jsonpatch — Jsonpatch v0.11.0

Post #6