Decouple the library from the example

The current demo works really well, but it is rather painful to reuse.

My understanding is that dfu.js and dfuse.js were thought as an easily-reusable library, and that dfu-util.js is responsible for hooking up the library to the demo HTML.

The problem is, dfu-util.js still does some heavy lifting : for example, see the connect function which tries to figure out if a given device is DfuSe-compliant or not. Re-using this code currently means duplicating this function.

It would be very useful to have a minimal UI-less demo to make sure reusing this library is easy.

[devanlai]

I haven’t tried this personally (or Node.js, for that matter), but there is a Node.js implementation of the WebUSB spec that you could try: https://github.com/thegecko/webusb

[devanlai]

Yeah, dfu.js and dfuse.js are more or less directly ported from dfu-util, whereas dfu-util.js is a bit more interactive than the real dfu-util.

My initial thoughts for refactoring some of that logic would be to add a new connectDfuInterface function that would absorb the descriptor-reading code in connect and in the call to navigator.usb.requestDevice. The user could then pass in an async callback to handle selecting the interface (which could either be interactive or pick a known-in-advance interface by interface number, name, etc).