About 10 years ago we had a device build that emulated a keyboard, we went to an electronics specialist and he made it. We used it to measure keypress to recognition of the machine accepting that event, the key press was a knows intervals so we could gather accepted margins of error on how fast someone was able to react to an onscreen event by pressing a key on the keyboard. This was a custom piece of hardware. Unfortunately I cannot remember where we had this made.

Also use css-modules, be aware that this will change the class names of the html thats rendered which may impact functional testing using selenium and css selectors by classname.

You will probably find more modern examples with ES6 and classes, this is generally a good thing. Code feels a little more "natural" this way aswell.