Building Web Serial API on @serialport/bindings

[cjihrig]

I have a WIP implementation of the Web Serial API built on @serialport/bindings. I've run into a few issues. I'm not sure if these are gaps in the serialport bindings, or if I'm just missing things.

All of the issues are called out in TODO comments in this file that mention the bindings layer. The current issues are:

• Are non-blocking reads supported? I think this is needed for the readable stream used by the API.
• Is it possible to only flush the receive buffer? I think this is needed for cancelling the readable stream.
• Is it possible to only flush the send buffer? I think this is needed for aborting the writable stream.
• Is it possible to set flow control? I think this is required for the open() API.
• Is it possible to get the RI signal? I think this is required for the getSignals() API.

As a side note, if this implementation could get to a good state, I'd be happy to turn it over to the serialport project.

[reconbot]

I'll start with the easy one. All reads are async, they return promises and guarantee at least one byte. Writes are async too, they resolve when all bytes have been written to the os.

[cjihrig]

@reconbot (or anyone else) do you have any input on the other items?

[GazHank]

You can get and set control flow info using the appropriate methods E.g. https://serialport.io/docs/api-stream#serialportset