def test_weight_loss():
"""Test that the animals loses weight each year."""
herb = Herbivore(9, 30)
herb.weight_loss()
carn = Carnivore(9, 40)
carn.weight_loss()
assert herb.weight != 30
assert herb.weight == 28.5
assert carn.weight != 40
assert carn.weight == 35
def test_fitness_weight_loss():
"""Test that the fitness changes with weight loss."""
herb = Herbivore(5, 10)
fitness_before_herbivore = herb.fitness
carn = Carnivore(5, 30)
fitness_before_carnivore = carn.fitness
herb.weight_loss()
carn.weight_loss()
fitness_after_herbivore = herb.fitness
fitness_after_carnivore = carn.fitness
assert fitness_before_herbivore != fitness_after_herbivore
assert fitness_before_carnivore != fitness_after_carnivore
