A list of file extensions is the kind of thing that seems to often get forgotten, causing some new extension to not work, and then you have an extra few months

A list of file extensions is the kind of thing that seems to often get forgotten, causing some new extension to not work, and then you have an extra few months in between the report and the PR making it into the release. Plus, if, at some point, people decide that extension checking is not enough, that can be added here, and the fix shared with everyone. It's future proofing to separate that into a reusable project. It's kind of excessive, and if it were me I would probably not think to even look for a library, or else I would want a more powerful and generic file type identification tool, even if at the moment I only needed video, I'd just let the tree shaker clean up the stuff I wasn't using. But I don't really have much of a problem with it. Unless of course, there's no testing process in place to be sure they don't release sabotageware. Being widely trusted doesn't matter as much in the age of neokaczynski types and various others who get disillusioned with tech in general.