$validParent = true;
foreach ($node->children as $childNode) {
if ($childNode->parent !== $node) {
$validParent = false;
}
}
(yield check($node->indexOf($secondChild) === 1, 'Second child not 1'));
(yield check($node->indexOf($thirdChild) === 0, 'Third child not 0'));
(yield check($validParent, 'Parent not correctly set'));
}, 'remove' => function () {
$node = new Node('parent');
$node->append(new Node('child-1'));
$node->append($secondChild = new Node('child-2'));
$node->append($thirdChild = new Node('child-3'));
$notAChild = new Node('not-a-child');
$node->remove($secondChild);
(yield check($node->indexOf($secondChild) === false, 'Child still in parent node'));
(yield check($secondChild->parent === null, 'Childs parent not null'));
(yield check($node->indexOf($thirdChild) === 1, 'Third child not moved to 1'));
}, 'insertAfter' => function () {
$node = new Node('parent');
$node->append($firstChild = new Node('child-1'));
$node->append($secondChild = new Node('child-2'));
$node->insertAfter($firstChild, $thirdChild = new Node('child-3'));
$notAChild = new Node('not-a-child');
(yield check(count($node->children) === 3, 'Child count not 3'));
(yield check($node->indexOf($thirdChild) === 1, 'Third child not 1'));
(yield check($node->indexOf($secondChild) === 2, 'Second child not 2'));
}, 'insertBefore' => function () {
$node = new Node('parent');
$node->append($firstChild = new Node('child-1'));
