Test for real#
It passes, but this does not give us any information about our code. Let's replace it with actual tests:
def test_migratory():
"""Test that the European swallow is migratory, while the African swallow is
not."""
european_swallow = Swallow(species="european")
assert european_swallow.is_migratory()
african_swallow = Swallow(species="african")
assert not african_swallow.is_migratory()
def test_unladen_velocity():
"""Test that unladen swallows fly at 60 km/h."""
european_swallow = Swallow(species="european", cargo_weight=0)
assert european_swallow.get_speed() == 60.0
african_swallow = Swallow(species="african")
assert african_swallow.get_speed() == 60.0
These tests are naive (see next sections) but they work. Or... do they? That's right, test_migratory should actually not pass.
Why is that?
It seems we were a bit too fast writig our code and we made a mistake. Is it thecode or the test that is wrong? The European swallows should be migratory, which is what the tests checks. Indeed, there is a mistake in the code return self.species == SwallowSpecies.AFRICAN should actually be: return self.species == SwallowSpecies.EUROPEAN
Good that we tested our code!
Writing the tests before implementing the code is called test-driven development and you might want take this approach when coding.
updated: 2023-04-20
