def test_remove_with_one_node():
"""Test remove if only one node."""
from dll import Dll
test_dll = Dll()
test_dll.push('target')
test_dll.remove('target')
assert test_dll.head is None
def test_remove_head():
dll = Dll()
dll.append(500)
dll.append(600)
dll.append(700)
dll.remove(500)
assert dll.head.value == 600
assert dll.head.next_node is dll.tail
assert dll.head.prev is None
def test_remove_tail():
dll = Dll()
dll.insert(500)
dll.insert(600)
dll.insert(700)
dll.remove(500)
assert dll.tail.value == 600
assert dll.tail.prev is dll.head
assert dll.tail.next_node is None
def test_remove_to_ensure_node_no_longer_exists():
"""Test remove method to ensure node is gone once remove is called."""
from dll import Dll
test_dll = Dll()
test_dll.push(11)
test_dll.push('target')
test_dll.push(34)
test_dll.remove('target')
with pytest.raises(ValueError):
test_dll._linkedlist.search('target')
def test_remove():
dll = Dll()
dll.insert(500)
dll.insert(600)
back = dll.head
dll.insert(700)
dll.insert(800)
front = dll.head
dll.insert(900)
dll.remove(700)
assert back.prev is front
assert front.next_node is back
def test_remove_head_of_list_with_multiple_nodes():
"""Test for remove method on list with multiple nodes."""
from dll import Dll
test_dll = Dll()
test_dll.push(11)
test_dll.push('target')
check = test_dll.head
assert test_dll.remove('target') == check
def test_remove_returns_node():
"""Test that correct node returned from search."""
from dll import Dll
test_dll = Dll()
test_dll.push(11)
test_dll.push('target')
check = test_dll.head
test_dll.push(34)
assert test_dll.remove('target') == check
def test_remove_with_empty_list():
"""Test to ensure error raised if remove called on empty list."""
from dll import Dll
test_dll = Dll()
with pytest.raises(IndexError):
test_dll.remove('a thing')
def test_remove_not_found():
dll = Dll()
dll.append(600)
dll.insert(700)
with pytest.raises(LookupError):
dll.remove(500)
def test_remove_empty():
dll = Dll()
with pytest.raises(LookupError):
dll.remove(500)
