def test_turn_with_invalid_turn_raises_invalid_turn(): heading.turn(None, heading.headings.NORTH)
def test_turn_left(): for left, right in turns: assert_equals(heading.turn(direction.LEFT, right), left)
def test_turn_with_invalid_heading_raises_invalid_turn(): heading.turn(direction.LEFT, None)
def test_turn_right(): for left, right in turns: assert_equals(heading.turn(direction.RIGHT, left), right)