def test_peek_one_item_one_queue(self):
value = 5
queue = FifoQueue()
queue.enqueue(value)
peeked_value = queue.peek()
self.assertEqual(1, queue.size)
self.assertEqual(5, peeked_value)
def test_peek_multiple_items_on_queue(self):
value1, value2, value3 = 5, 10, 15
queue = FifoQueue()
queue.enqueue(value1)
queue.enqueue(value2)
queue.enqueue(value3)
peeked_item = queue.peek()
self.assertEqual(3, queue.size)
self.assertEqual(5, peeked_item)
def test_peek_no_items_on_queue(self):
queue = FifoQueue()
peeked_value = queue.peek()
self.assertEqual(0, queue.size)
self.assertEqual(None, peeked_value)
