Get serialnumber from usb

[JesperBadstue]

• Added parameter for getting serial number from usb during discovery.
• Formatting updates.

[tr3v3r]

Could you please give me an example of serial number of the device?
I'm asking because it seems that we already have it in target returned by the discovery listener.

I suppose numbers after USB: is the serial number. Isn't it?

[tr3v3r]

Moreover, I think we should have a possibility to get SN using any type of connection.
I think I'll add the corresponding method this week

[JesperBadstue]

I agree that it would be best to get the serialnumber from the getPrinterInformationunfortunately it seemed to be unstable on my devices. It only returned data approx every 2. time and the data was empty .eg. "SerialNumber:" "".
Therefore I used the UsbManagerto get the serialnumber as it seemes to be more reliable.

An example output of this PR is:
[{"bt": "", "ip": "", "mac": "", "name": "TM Printer", "serial": "513650463513220000", "target": "USB:/dev/bus/usb/004/005", "usb": "/dev/bus/usb/004/005"}]

Options for the discover would be EscPosPrinter.discover({ serialNumber: true, });

I dont think the DiscoveryListener returns the serial number. From what I can see from you screenshot it means that we can connect to a usb device by using the serial. The serial seems to only be available from getPrinterInformation() og the UsbManager as I think that you have to open/connect to the device to get the serial and the discoverprocess does not open the device.

[tr3v3r]

Ok. I've got your point. Since your task is too specific, I suppose we need to make some changes before merging.
See comments

[JesperBadstue]

If you still want to implement the usage og getPrinterInformation() you are welcome to ping me and I will test it on my device (An Epson TM-88V)

[tr3v3r]

I'm afraid your printer is not supported by this method

[tr3v3r]

But anyway if we really need it I'll add it.

[JesperBadstue]

Aaah, that explains why the function did not really work for me :) I was sure that I checked that it was supported but apparently I did not.

[tr3v3r]

It's strange for me that this method works on limited printer series.

Could you please resolve conversations after you make corresponding changes?

I'll test it on iOS as well soon ( I don't remember if it's OK to pass params without declaring it on the native side - it may cause crash )

[tr3v3r]

Merged. I'll test on iOS today later on and push a new version to npm. Thanks