getInfo method should not reject before opening the port

[stylesuxx]

In the "real" Web Serial API one can query information about the available ports before opening a connection:

const ports = await serial.getPorts();
const info = await ports[0].getInfo();

But results in a rejection with the polyfill:

DOMException: The device must be opened first

[reillyeon]

The current implementation of getInfo() actually doesn't match the specification at all. It returns a SerialOptions rather than a SerialPortInfo. That's why it requires the device to be open, so it can read back the current device configuration. If it returned a SerialPortInfo that could be constructed only from attributes of the underlying USBDevice interface.

[stylesuxx]

I understand. But in order to be closer to the Web Serial implementation, it should not reject. Otherwise I would need to again have checks in place if the polyfill or the real deal is used - which is not what I should be having to do when using a polyfill.

If device info is not available would it not be an option to simply return some dummy data for vendor and product id?

[reillyeon]

This was fixed in #21.