def test_pop_empty(self):
t = FIFO()
with pytest.raises(IndexError):
t.pop()
t.append(None)
t.pop()
with pytest.raises(IndexError):
t.pop()
def test_lots(self):
t = FIFO()
for i in range(1000):
t.append(i)
for i in range(500):
assert i == t.pop()
for i in range(1000, 1500):
t.append(i)
assert i - 500 == t.pop()
def test_len(self):
t = FIFO()
assert 0 == len(t)
t.append(0)
assert 1 == len(t)
t.append(0)
assert 2 == len(t)
t.pop()
assert 1 == len(t)
def test_order(self):
t = FIFO()
t.append('cat')
t.append('dog')
assert 'cat' == t.pop()
assert 'dog' == t.pop()
