def test_delete_next_reassignment():
l = Slist()
l.prepend("Bob")
l.prepend("Dave")
l.prepend("Amy")
l.prepend("Carol")
l.delete("Amy")
l.delete("Dave")
assert l.head.next.key == "Bob"
def test_delete():
l = Slist()
l.prepend("Bob")
l.prepend("Amy")
l.prepend("Carol")
l.delete("Carol")
assert l.head.key == "Amy"
l.delete("Bob")
assert l.head.next is None
l = Slist()
l.prepend("Bob")
l.prepend("Amy")
l.prepend("Carol")
with pytest.raises(ValueError):
l.delete("Edgar")
l = Slist()
with pytest.raises(ValueError):
l.delete("Edgar")
