def it_errors_when_lab_is_too_small():
lab = Laboratory("apprentice lab")
with pytest.raises(ValueError):
lab.set_size(-6)
lab.set_size(-5)
with pytest.raises(ValueError):
lab.decrease_size()
def it_can_decrease_size():
lab = Laboratory("apprentice lab")
lab.decrease_size()
assert lab.size == -1
lab.decrease_size(2)
assert lab.size == -3