JsonPatcher

JsonPatcher is a mod that allows you to modify json files in datapacks and resourcepacks without overriding them.
This is primarily useful for mod developers and pack makers, but can also be used by players to modify their own packs.

V2 Disclaimer

JsonPatcher v2 is currently in beta. V2 introduces a bunch of new features including global patches for mods and modpacks.
Documentation for v2 is available at jsonpatcher-docs.mattidragon.dev.
The documentation is however quite incomplete and partially outdated.
For some cases it might be best to consult the old wiki instead.

Usage

repositories {
    maven {
        url 'https://jitpack.io'
    }
}

dependencies {
    modImplementation(include("com.github.mattidragon:jsonpatcher:${jsonpatcher_version}"))
}

To begin using jsonpatcher, just create a file with the .jsonpatch extension
in the data/<namespace>/jsonpatch directory of your datapack
or assets/<namespace>/jsonpatch directory of your resourcepack.

You'll want to begin your patch with a @version meta tag like this.
This will let jsonpatcher know that your patch will work with this version.
In the future you may be able to select a version in more ways.

@version "1"

Next you'll want to select the files you want to patch.
This is done with the @target meta tag. All meta tags follow a json format.
You can either select a single file with a string, use an object for broader selections,
or use an array for multiple selections. If any selector in the array matches, the patch will apply.

Now you can begin modifying the target file. The patch files use a c-like syntax.
You can access the target files contents with $. It can be used like a variable,
or you can put the property you want to access directly after it.

For more info on the language, see the wiki.