def test_append():
u"""Assert .append() adds a value to the t of the doubly linked list."""
doubly_linked = DoublyLinked()
for val in VALUES:
doubly_linked.append(val)
assert doubly_linked.tail.value == val
assert doubly_linked.tail.value == VALUES[-1]
def test_insert():
u"""Assert .insert() adds value/node to the h of the doubly linked list."""
doubly_linked = DoublyLinked()
for val in VALUES:
doubly_linked.insert(val)
assert doubly_linked.head.value == val
assert doubly_linked.head.value == VALUES[-1]
def test_shift():
u"""Assert .shift() removes and returns the t value from the list."""
doubly_linked = DoublyLinked()
for val in VALUES:
doubly_linked.insert(val)
for val in VALUES:
assert doubly_linked.shift() == val
assert doubly_linked.shift() is None
def test_pop():
u"""Assert .pop() removes and returns the h value from the list."""
doubly_linked = DoublyLinked()
for val in VALUES:
doubly_linked.append(val)
for val in VALUES:
assert doubly_linked.pop() == val
assert doubly_linked.pop() is None
def test_remove():
u"""Assert .remove() removes the first matching value from the list."""
doubly_linked = DoublyLinked()
for val in VALUES:
doubly_linked.insert(val)
test_vals = VALUES[:]
while test_vals:
val = random.choice(test_vals)
doubly_linked.remove(val)
test_vals.remove(val)
assert doubly_linked.pop() is None
assert doubly_linked.head is None
assert doubly_linked.tail is None
doubly_linked.insert(1)
with pytest.raises(LookupError):
doubly_linked.remove("test value")
def test_DoublyLinked_init():
u"""Assert a DoublyLinked list instantiates with a given values."""
doubly_linked = DoublyLinked()
assert isinstance(doubly_linked, DoublyLinked)
