ff-diff

ff-diff is a simple node script to compare changes in user.js preference files between two versions of Firefox. You don't need to mess with your firefox instance.

Features:

• Compares user.js files from two specified Firefox versions
• Automatically downloads official Firefox binaries
• Highlights differences without requiring a local Firefox installation

Requirements:

• Internet connection (for downloading Firefox binaries)
• node >= 20 and npm
• tar

Installation (NPM)

npm i -g ff-diff

Usage

$ ff-diff
Usage:
  ff-diff clean [--keep <version1>,<version2>] [--keep-archives] [--keep-sources]
  ff-diff <version1> <version2> [--clean-archives] [--clean-sources] [--do-not-print-diffs-in-console] [--save-diffs-in-file] [--compare-userjs <path>]

Example:

ff-diff 137.0 138.0

Develop

Clone this repository:

git clone https://github.com/martabal/ff-diff.git
cd ff-diff
npm ci

Run the comparison script:

npm run ff-diff <version1> <version2>

for example:

npm run ff-diff 137.0 138.0

If you use a custom user.js. You can check if some of the keys are removed/changed with the argument --compare-userjs <path_to_your_userjs>.

Clean

When running the script in development mode with npm run dev, Firefox sources and binaries are saved in the current directory. In production mode (i.e., when the script is installed globally using npm i -g ff-diff), these files are stored in ~/.ff-diff.

By default, the script keep both the downloaded archives and the extracted source files. To remove them, you can run the script with the --remove-archives and/or --remove-sources arguments. If you want to use specific version you can use:

npm run ff-diff clean -- --keep <version1>,<version2>

If you want to only keep archives you can use npm run clean -- --keep <version1>,<version2> --keep-archives or npm run clean -- --keep <version1>,<version2> --keep-sources if you want to keep the sources

Note

The script may take some time to run depending on your connection speed.

Example of a generated diffs:

`