car interfaces: assert some friction (#28074)

* assert some friction

* duh

* convention

* order

selfdrive/car/tests/test_car_interfaces.py

@@ -6,9 +6,9 @@ from parameterized import parameterized
 
 from cereal import car
 from selfdrive.car import gen_empty_fingerprint
-from selfdrive.car.fingerprints import all_known_cars
 from selfdrive.car.car_helpers import interfaces
-from selfdrive.car.fingerprints import _FINGERPRINTS as FINGERPRINTS
+from selfdrive.car.fingerprints import _FINGERPRINTS as FINGERPRINTS, all_known_cars
+
 
 class TestCarInterfaces(unittest.TestCase):
 
@@ -51,7 +51,7 @@ class TestCarInterfaces(unittest.TestCase):
 
       elif tune.which() == 'torque':
         self.assertTrue(not math.isnan(tune.torque.kf) and tune.torque.kf > 0)
-        self.assertTrue(not math.isnan(tune.torque.friction))
+        self.assertTrue(not math.isnan(tune.torque.friction) and tune.torque.friction > 0)
 
       elif tune.which() == 'indi':
         self.assertTrue(len(tune.indi.outerLoopGainV))