def test_linked_list_unlink_first():
ll = LinkedList()
n1 = ll.append(42)
n2 = ll.append('fnord')
n3 = ll.append([0, 1, 2])
n1.unlink()
assert list(ll) == ['fnord', [0, 1, 2]]
assert list(ll.iternodes()) == [n2, n3]
assert ll.find_node(n1) is None
assert ll.find_node(n2) == 0
assert ll.find_node(n3) == 1
assert ll.start is n2
assert ll.end is n3
assert n2.prev is None
assert n2.next is n3
assert n3.prev is n2
assert n3.next is None
def test_linked_list_unlink_middle():
ll = LinkedList()
n1 = ll.append(42)
n2 = ll.append('fnord')
n3 = ll.append([0, 1, 2])
n2.unlink()
assert list(ll) == [42, [0, 1, 2]]
assert list(ll.iternodes()) == [n1, n3]
assert ll.find_node(n1) == 0
assert ll.find_node(n2) is None
assert ll.find_node(n3) == 1
assert ll.start is n1
assert ll.end is n3
assert n1.prev is None
assert n1.next is n3
assert n3.prev is n1
assert n3.next is None
def test_linked_list_unlink_last():
ll = LinkedList()
n1 = ll.append(42)
n2 = ll.append('fnord')
n3 = ll.append([0, 1, 2])
n3.unlink()
assert list(ll) == [42, 'fnord']
assert list(ll.iternodes()) == [n1, n2]
assert ll.find_node(n1) == 0
assert ll.find_node(n2) == 1
assert ll.find_node(n3) is None
assert ll.start is n1
assert ll.end is n2
assert n1.prev is None
assert n1.next is n2
assert n2.prev is n1
assert n2.next is None
def test_linked_list_unlink_only():
ll = LinkedList()
n = ll.append(42)
n.unlink()
assert list(ll) == []
assert list(ll.iternodes()) == []
assert ll.start is None
assert ll.end is None
assert ll.find_node(n) is None
def test_linked_list_three_elem():
ll = LinkedList()
n1 = ll.append(42)
n2 = ll.append('fnord')
n3 = ll.append([0, 1, 2])
assert list(ll) == [42, 'fnord', [0, 1, 2]]
assert list(ll.iternodes()) == [n1, n2, n3]
assert ll.find_node(n1) == 0
assert ll.find_node(n2) == 1
assert ll.find_node(n3) == 2
assert ll.start is n1
assert ll.end is n3
assert n1.prev is None
assert n1.next is n2
assert n2.prev is n1
assert n2.next is n3
assert n3.prev is n2
assert n3.next is None
def test_linkedlist_one_elem():
ll = LinkedList()
n = ll.append(42)
assert list(ll) == [42]
assert list(ll.iternodes()) == [n]
assert ll.find_node(n) == 0
assert ll.start is n
assert ll.end is n
assert n.prev is None
assert n.next is None
def test_linked_list_insert_after_last():
ll = LinkedList()
n1 = ll.append(42)
n2 = ll.append('fnord')
n3 = ll.append([0, 1, 2])
nx = n3.insert_after(3.14)
assert list(ll) == [42, 'fnord', [0, 1, 2], 3.14]
assert list(ll.iternodes()) == [n1, n2, n3, nx]
assert ll.find_node(n1) == 0
assert ll.find_node(n2) == 1
assert ll.find_node(n3) == 2
assert ll.find_node(nx) == 3
assert ll.start is n1
assert ll.end is nx
assert n1.prev is None
assert n1.next is n2
assert n2.prev is n1
assert n2.next is n3
assert n3.prev is n2
assert n3.next is nx
assert nx.prev is n3
assert nx.next is None
def test_linked_list_insert_before_first():
ll = LinkedList()
n1 = ll.append(42)
n2 = ll.append('fnord')
n3 = ll.append([0, 1, 2])
nx = n1.insert_before(3.14)
assert list(ll) == [3.14, 42, 'fnord', [0, 1, 2]]
assert list(ll.iternodes()) == [nx, n1, n2, n3]
assert ll.find_node(n1) == 1
assert ll.find_node(n2) == 2
assert ll.find_node(n3) == 3
assert ll.find_node(nx) == 0
assert ll.start is nx
assert ll.end is n3
assert nx.prev is None
assert nx.next is n1
assert n1.prev is nx
assert n1.next is n2
assert n2.prev is n1
assert n2.next is n3
assert n3.prev is n2
assert n3.next is None
def test_linkedlist_two_elem():
ll = LinkedList()
n1 = ll.append(42)
n2 = ll.append('fnord')
assert list(ll) == [42, 'fnord']
assert list(ll.iternodes()) == [n1, n2]
assert ll.find_node(n1) == 0
assert ll.find_node(n2) == 1
assert ll.start is n1
assert ll.end is n2
assert n1.prev is None
assert n1.next is n2
assert n2.prev is n1
assert n2.next is None