The Extension Update Testing Tool is a local extension update server that can be used for testing updates to Chrome Extensions during local development, including permission grants.

This tool serves a number of use cases:

• Testing what permission warnings are generated for specific changes in the manifest.json file.
• Seeing the update flow, including how an extension is disabled until a user grants additional permissions.
• Testing migration logic between versions (this is possible by simply reloading an extension, but using the update logic is closer to what happens when updating from the Chrome Web Store).

It is particularly useful for (but not limited to) migrations to Manifest V3, since this often involves changes to the permissions an extension requests.

1. Install Node.js and NPM: https://nodejs.org/
2. Clone this repository.
3. Run npm install in the root of the repository.

1. Run npm start.
2. Open the local server at http://localhost:8080.
3. Drag an unpacked extension (folder or .zip file) to the page.
4. Follow the instructions to install the extension.
5. Drag an updated extension to the page, making sure to update the version field in the manifest.json file.
6. Click "Update" at chrome://extensions to see the extension update.

You can configure the port of the local server using the PORT environment variable, e.g:

PORT=4000 npm start

You can also use WRITE_KEY to write a private key locally and have a consistent extension ID across restarts, e.g:

WRITE_KEY=1 npm start

This happens if you try to use the policy install methods but haven't set the required policy keys. If you've already set these, you may need to click "Reload policies" at chrome://policy.

This project was inspired by many great community projects, including https://github.com/thom4parisot/crx.

Contributions are welcome. See How to Contribute for more information on how to get involved.