Patched

New Features

• Patches can now be applied to tags/sounds json/blockstates(?)/etc. or so-called "merged files". These only work for files defined in the same pack. That is, you cannot patch a tag defined by Minecraft (although you could patch your own contributions to it). This opens up the possibility for configurable tags, among other things.

New Features (modder-facing)

• Added the paste patch type, which allows 'pasting' arbitrary code-defined data in json files. The intended purpose of this patch type is to make it possible to get config values into otherwise-unconfigurable things like biomes. For example, making a feature's spawn rate configurable without needing data packs. See the documentation and SingleDataSource for more information.
• On (Neo)Forge, mods may now use IMC (InterModComms) to register data sources (for the paste operation) and test conditions (for test patches with a type field). See the documentation for details.

Changes (modder-facing)

• Custom test registration has changed — they are now registered using Patched.registerTestCondition() and Patched.registerSimpleTestCondition(). Test conditions registered the old way will still work.