react-addons-update

A legacy React addon providing a simple immutability helper, `update()`, for updating nested objects and arrays in an immutable fashion using MongoDB-like query syntax. Version 15.6.3 is the last release; it is no longer maintained and is deprecated. Recommended replacement is `immutability-helper` v1.0.0+ (drop-in). The library is ESM and CJS compatible. Key differentiator: syntactic sugar over manual shallow copying with `$set`, `$push`, `$splice`, etc. Not recommended for new code due to deprecation.