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 queue_vals():
queue = Queue()
queue.enqueue(8)
queue.enqueue('hi')
queue.enqueue(-4)
queue.enqueue(6)
return queue
def test_enqueue(queue_vals):
# no nodes
q = Queue()
assert q.front == None
assert q.rear == None
# only one node
q.enqueue(5)
assert q.front.value == 5
assert q.rear.value == 5
# two nodes
q.enqueue(7)
assert q.front.value == 5
assert q.rear.value == 7
assert queue_vals.rear.value == 6
assert queue_vals.front.value == 8
def test_peek():
q = Queue()
q.enqueue("apple")
q.enqueue("banana")
q.enqueue("cucumber")
actual = q.peek()
expected = "apple"
assert actual == expected
def test_peek_post_dequeue():
# TODO it should return a new first value if peek is called after a dequeue
q = Queue()
q.enqueue("apples")
q.enqueue("bananas")
q.enqueue("grapes")
q.dequeue()
actual = q.peek()
expected = "bananas"
assert actual == expected
def test_exhausted():
# TODO TODO is empty should return true after dequeueing all previously queued items
q = Queue()
q.enqueue("apples")
q.enqueue("bananas")
q.enqueue("grapes")
q.dequeue()
q.dequeue()
q.dequeue()
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