When a file is uploaded as part of a form submission, its MIME is included. I've discovered that Firefox on Windows has an inconvenient way of determining this MIME.
The short answer, it turns out that Axios knows what to do with a Buffer object.
An introduction to the FileReader interface and where its strengths lie in AJAX file uploads.
React portals are a powerful tool, but have some gotchas that you should be aware of.
A guide to building a website from start to finish. Get your site out instead of your hair.