def test_push_front(self):
deque = new_deque()
deque.push_front(1)
assert deque.front == 1
assert deque.back == 1
deque.push_front(2)
assert deque.front == 2
assert deque.back == 1
def test_properties(self):
items = collection()
deque = new_deque(copy.deepcopy(items))
assert deque.is_empty() is False
assert deque.size == len(items)
assert deque.clear() == 0
assert deque.is_empty() is True
assert deque.size == 0
def test_pop_front_with_one_item(self):
deque = new_deque()
deque.push_front(1)
assert deque.front == 1
assert deque.back == 1
val = deque.pop_front()
assert val == 1
assert deque.clear() == 0
assert deque.is_empty() is True
assert deque.size == 0
def test_push_back(self):
deque = new_deque()
deque.push_back(1)
assert deque.front == 1
assert deque.back == 1
deque.push_back(2)
assert deque.front == 1
assert deque.back == 2
deque.push_back(3)
assert deque.front == 1
assert deque.back == 3
def test_pop_back(self):
deque = new_deque()
items = [1, 3, 2, 7]
expected = []
for x in items:
# preserve order for a test
deque.push_front(x)
for _ in range(0, len(items)):
expected.append(deque.pop_back())
assert items == expected