def test_push():
stck1 = Stack()
stck1.push(5)
assert stck1.top.value == 5
def test_pop_until_empty():
s = Stack()
s.push("apple")
s.push("banana")
s.push("cucumber")
s.pop()
s.pop()
s.pop()
actual = s.is_empty()
expected = True
assert actual == expected
def test_pop_empty():
s = Stack()
with pytest.raises(InvalidOperationError) as e:
s.pop()
assert str(e.value) == "Method not allowed on empty collection"
def test_push_onto_empty():
s = Stack()
s.push("apple")
actual = s.top.value
expected = "apple"
assert actual == expected
def test_pop_some():
s = Stack()
s.push("apple")
s.push("banana")
s.push("cucumber")
s.pop()
actual = s.pop()
expected = "banana"
assert actual == expected
def test_pop_single():
s = Stack()
s.push("apple")
actual = s.pop()
expected = "apple"
assert actual == expected
def test_connection():
return Stack()
def __init__(self):
self._stack1 = Stack()
self._stack2 = Stack()