def test_bft_stop_iteration():
"""Test that iteration stops."""
a = BST([1, 2, 4])
b = a.bft()
with pytest.raises(StopIteration):
next(b)
next(b)
next(b)
next(b)
def test_delete_node_with_child():
"""Test that nodes are rearranged after delete."""
a = BST([5, 4, 6, 3, 4.5, 4.6, 7, 5.5])
a.delete(4.5)
b = a.bft()
result = []
for i in range(7):
result.append(next(b))
assert result == [5, 4, 6, 3, 4.6, 5.5, 7]