Patch-package is a utility that extends JavaScript package managers to capture and reapply local modifications made to installed third-party dependencies. By generating standard diff files from changes made directly to the source code on disk, it allows developers to maintain custom fixes across dependency updates and team environments without the need to fork or publish modified versions of external libraries.
The tool integrates directly into the package manager lifecycle, automatically applying stored patches after dependencies are installed or updated. It supports complex maintenance scenarios by allowing multiple patches per dependency, providing mechanisms to revert changes, and offering configurable storage locations for patch files.
To ensure consistency across environments, the system includes features for conditional patch application and production exclusion, which prevent specific modifications from affecting production builds. It also provides error reporting to notify developers if a patch fails to apply, ensuring that any conflicts are identified during the build process.
