def test_peek_post_dequeue():
q = Queue()
q.enqueue("apples")
q.enqueue("bananas")
q.dequeue()
actual = q.peek()
expected = "bananas"
assert actual == expected
def test_peek():
q = Queue()
q.enqueue("apple")
q.enqueue("banana")
q.enqueue("cucumber")
actual = q.peek()
expected = "apple"
assert actual == expected
def test_dequeue_when_full():
q = Queue()
q.enqueue("apples")
q.enqueue("bananas")
actual = q.dequeue()
expected = "apples"
assert actual == expected
def test_enqueue_two():
q = Queue()
q.enqueue("apples")
q.enqueue("bananas")
actual = q.peek()
expected = "apples"
assert actual == expected
def test_dequeue():
q = Queue()
q.enqueue("apple")
q.enqueue("banana")
actual = q.dequeue()
expected = "apple"
assert actual == expected
def test_exhausted():
q = Queue()
q.enqueue("apple")
q.enqueue("banana")
q.enqueue("cucumber")
q.dequeue()
q.dequeue()
q.dequeue()
actual = q.is_empty()
expected = True
assert actual == expected
def test_is_empty():
q = Queue()
actual = q.is_empty()
expected = True
assert actual == expected
def test_enqueue():
q = Queue()
q.enqueue("apple")
actual = q.front.value
expected = "apple"
assert actual == expected
def test_dequeue_when_empty():
q = Queue()
with pytest.raises(InvalidOperationError):
q.dequeue()
def test_peek_when_empty():
q = Queue()
with pytest.raises(InvalidOperationError):
q.peek()