def test_BST():
bst = BST()
# Test empty tree
assert (len(bst.BFS()) == 0)
# Test insert
bst.insert(2)
bst.insert(3)
bst.insert(1)
assert (len(bst.BFS()) == 3)
expected = [2, 1, 3]
actual = [node.value for node, l in bst.BFS()]
assert_(expected, actual)
# Test search
assert (bst.search(2) is True)
assert (bst.search(5) is False)
# Test-1 Pre Order Traversal
bst.insert(0)
pre_order_expected = [2, 1, 0, 3]
pre_order_actual = bst.pre_order_traversal()
assert_(pre_order_expected, pre_order_actual)
# Test-2 In-Order Traversal
in_order_expected = [0, 1, 2, 3]
in_order_actual = bst.in_order_traversal()
assert_(in_order_expected, in_order_actual)
# Test-3 Post-Order Traversal
post_order_expected = [0, 1, 3, 2]
post_order_actual = bst.post_order_traversal()
assert_(post_order_expected, post_order_actual)
# Test-4 Delete
bst.delete(3)
delete_expected_output = [0, 1, 2]
delete_actual_output = bst.post_order_traversal()
assert_(delete_expected_output, delete_actual_output)
# Test-5 Delete
bst.insert(5)
bst.insert(4)
bst.insert(8)
bst.insert(6)
bst.insert(9)
delete_expected_output = [0, 1, 2, 4, 6, 8, 9]
bst.delete(5)
delete_actual_output = bst.in_order_traversal()
assert_(delete_expected_output, delete_actual_output)
