How to use Bluetooth hid

Sorry, I don't see where you get the variable length from, the ble_hid­_keyboard.js also does only 8 arguments? According to the source the function accepts different length. Still I don't know if 9 arguments is correct since I have not read the hid documentation yet. Also jswrap_ble_sendHIDReport() states:

Send a USB HID report. HID must first be enabled with NRF.setServices({}, {hid: hid_report})

so the setServices() call is really missing here.