duckduckgo-site-search

Google Chrome extension which adds a Search this site button next to the DuckDuckGo search results, allowing for refined searches within the domain of the result.

Installation:

The extension is unpacked, so to load it, you need to follow the steps described here. Upload the root folder of the extension when prompted.

How it works:

All the extension logic relies on the content_scripts. On the window load event, the search results are queried from the DOM. A MutationObserver is set up to monitor changes in the search results container, allowing to handle the case where new search results are displayed on the page (i.e. the More Results button is clicked). For each search result with a valid URL, a Search this site button is appended using the DOM API. Parsing the URL relies on the URL interface. If the URL constructor throws an error, the button for the link won't be appended. To perform a new search, the search input value is changed to <query> site:<hostname>, and a click event is triggered on the search button.

Known issues and limitations:

1. No tests. Unit and e2e tests would increase the reliability of the extension and reduce the number of bugs;

2. The extension is not packaged and not published to the Chrome Web Store, making it harder to install, less secure, and less performant;

3. It hasn't been tested for compatibility issues with Google Chrome versions other than 124.0.6367.79;

4. The extension is highly dependent on the DOM of the DuckDuckGo site, so if they change something, the extension may not work properly. That's why the selectors have been moved to a separate single file to make them easier to change in such cases;

5. It has limited functionality. It only works in DuckDuckGo, although it could be modified to work in multiple search engines. There is no way to customize the Search this site button, nor any way to easily toggle it.