#!/usr/bin/env python

"""

Tests helpers in `can.interfaces.socketcan.socketcan_common`.

"""

import gzip

from base64 import b64decode

import unittest

from unittest import mock

from subprocess import CalledProcessError

from can.interfaces.socketcan.utils import find_available_interfaces, error_code_to_str

from .config import IS_LINUX, TEST_INTERFACE_SOCKETCAN

class TestSocketCanHelpers(unittest.TestCase):

@unittest.skipUnless(IS_LINUX, "socketcan is only available on Linux")

def test_error_code_to_str(self):

"""

Check that the function does not crash & always

returns at least one character.

"""

# all possible & also some invalid error codes

test_data = list(range(0, 256)) + [-1, 256, 5235, 346264, None]

for error_code in test_data:

string = error_code_to_str(error_code)

self.assertTrue(string) # not None or empty

@unittest.skipUnless(

TEST_INTERFACE_SOCKETCAN, "socketcan is only available on Linux"

)

def test_find_available_interfaces(self):

result = find_available_interfaces()

self.assertGreaterEqual(len(result), 3)

self.assertIn("vcan0", result)

self.assertIn("vxcan0", result)

self.assertIn("slcan0", result)

def test_find_available_interfaces_w_patch(self):

# Contains lo, eth0, wlan0, vcan0, mycustomCan123

ip_output_gz_b64 = (

"H4sIAAAAAAAAA+2UzW+CMBjG7/wVhrNL+BC29IboEqNSwzQejDEViiMC5aNsmmX/+wpZTGUwDAcP"

"y5qmh+d5++bN80u7EXpsfZRnsUTf8yMXn0TQk/u8GqEQM1EMiMjpXoAOGZM3F6mUZxAuhoY55UpL"

"fbWoKjO4Hts7pl/kLdc+pDlrrmuaqnNq4vqZU8wSkSTHOeYHIjFOM4poOevKmlpwbfF+4EfHkLil"

"PRo/G6vZkrcPKcnjwnOxh/KA8h49JQGOimAkSaq03NFz/B0PiffIOfIXkeumOCtiEiUJXG++bp8S"

"5Dooo/WVZeFnvxmYUgsM01fpBmQWfDAN256M7SqioQ2NkWm8LKvGnIU3qTN+xylrV/FdaHrJzmFk"

"gkacozuzZMnhtAGkLANFAaoKBgOgaUDXG0F6Hrje7SDVWpDvAYpuIdmJV4dn2cSx9VUuGiFCe25Y"

"fwTi4KmW4ptzG0ULGvYPLN1APSqdMN3/82TRtOeqSbW5hmcnzygJTRTJivofcEvAgrAVvgD8aLkv"

"/AcAAA=="

)

ip_output = gzip.decompress(b64decode(ip_output_gz_b64)).decode("ascii")

with mock.patch("subprocess.check_output") as check_output:

check_output.return_value = ip_output

ifs = find_available_interfaces()

self.assertEqual(["vcan0", "mycustomCan123"], ifs)

def test_find_available_interfaces_exception(self):

with mock.patch("subprocess.check_output") as check_output:

check_output.return_value = "<h1>Not JSON</h1>"

result = find_available_interfaces()

self.assertEqual([], result)

check_output.side_effect = Exception("Something went wrong :-/")

result = find_available_interfaces()

self.assertEqual([], result)

if __name__ == "__main__":

unittest.main()