def test_car_is_validating_position_with_road():
# On init
road = Road()
car1 = Car(road, position=2000)
assert car1.position == 0
# In update_position
car1 = Car(road, position=100, init_speed=10)
car2 = Car(road, position=500)
car1.position = 1000
car1.update_position(car2)
assert car1.position == 10
# In brake_if_needed
car1 = Car(road, position=1005, init_speed=10)
car2 = Car(road, position=10)
did_brake = car1.brake_if_needed(leading_car=car2)
assert did_brake is True
with mock.patch("random.random", return_value=1):
car1 = Car(road, position=500, init_speed=10)
car2 = Car(road, position=0)
did_brake = car1.brake_if_needed(leading_car=car2)
assert did_brake is False
assert car1.distance_behind(car2) == 495
def test_car_slows_if_over_desired_speed():
road = Road()
car1 = Car(road, init_speed=100, desired_speed=30)
car2 = Car(road, position=900)
with mock.patch("random.random", return_value=1):
# disable random braking
car1.brake_if_needed(leading_car=car2)
assert car1.speed == 30
with mock.patch("random.random", return_value=0.05):
# force random braking
car1.brake_if_needed(leading_car=car2)
assert car1.speed == 28
car1.speed = 100
car1.accelerate()
assert car1.speed == 30
def test_brake_if_needed():
# Stop if collision imminent
road = Road()
car1 = Car(road, position=200, init_speed=20)
car2 = Car(road, position=210)
with mock.patch("random.random", return_value=1):
did_brake = car1.brake_if_needed(leading_car=car2)
assert did_brake is True
assert car1.speed == 5
