def test_can_advance_TrapSeed_along_a_heading_and_loses_lifespan(
heading, column):
# Rather than patch heading_to_delta in TrapSeed.advance we just
# assert that the effect of advancing the TrapSeed matches that
# defined by heading_to_delta
expected_dx, expected_dy = heading_to_delta(heading, is_even(column))
trapSeed = TrapSeed(column, 5, heading, 10)
assert trapSeed.advance() == TrapSeed(column + expected_dx,
5 + expected_dy, heading, 9)
# Original instance is not actually changed
assert trapSeed == TrapSeed(column, 5, heading, 10)
def test_can_reverse_a_TrapSeed_along_a_heading_and_loses_lifespan():
trapSeed = TrapSeed(5, 5, 0, 10)
assert trapSeed.advance(reverse=True) == TrapSeed(5, 4, 180, 9)
# Original instance is not actually changed
assert trapSeed == TrapSeed(5, 5, 0, 10)