check-hid-enumeration-order.py

__version__ = '0.0.1'

import sys

if sys.platform.startswith('linux'):
    try:
        import hidraw
        hid = hidraw
    except:
        pass
else:
    import hid


def check_iters(iters):
    if not iters:
        raise ValueError('Not defined for iters == []')
    return iters[1:] == iters[:-1]


def print_hid_device_line(info):
    vid = info['vendor_id']
    pid = info['product_id']
    path = info['path'].decode()
    print(f'hid {vid:04x}:{pid:04x} on {path}')


if __name__ == "__main__":
    errors = 0
    args = sys.argv[1:]
    niters = int(args[0]) if args else 3
    print(f'Script to check the HID enumeration order, version {__version__}')
    print(f'Iteration count is {niters}')
    print()

    print('Checking: enumerate')
    iters = []
    for i in range(niters):
        print(f'iteration: {i}')
        order = []
        for info in hid.enumerate():
            print_hid_device_line(info)
            order.append(info['path'])
        iters.append(order)
    if check_iters(iters):
        print('passed')
    else:
        errors += 1
        print('FAILED')
    print()

    nhids = len(iters[0])
    print(f'HID count is {nhids}')
    print()

    print(f'Checking: enumerate, break after {nhids//2} HIDs')
    iters = []
    for i in range(niters):
        print(f'iteration: {i}')
        order = []
        cnt = 0
        for info in hid.enumerate():
            print_hid_device_line(info)
            order.append(info['path'])
            cnt += 1
            if cnt == nhids // 2:
                break
        iters.append(order)
    if check_iters(iters):
        print('passed')
    else:
        errors += 1
        print('FAILED')
    print()

    print(f'Checking: enumerate and open/close, break after {nhids//2} HIDs')
    iters = []
    for i in range(niters):
        print(f'iteration: {i}')
        order = []
        cnt = 0
        for info in hid.enumerate():
            print_hid_device_line(info)
            path = info['path']
            dev = hid.device()
            try:
                dev.open_path(path)
                dev.close()
            except:
                print('  ignoring: could not open')
            order.append(path)
            cnt += 1
            if cnt == nhids // 2:
                break
        iters.append(order)
    if check_iters(iters):
        print('passed')
    else:
        errors += 1
        print('FAILED')
    print()

    if not errors:
        print('all ok')
    else:
        print('SOME ERRORS WHERE FOUND')
        sys.exit(1)