in js/bootstrap.bundle.js [2494:2508]
function listScrollParents(element, list) {
var _element$ownerDocumen;
if (list === void 0) {
list = [];
}
var scrollParent = getScrollParent(element);
var isBody = scrollParent === ((_element$ownerDocumen = element.ownerDocument) == null ? void 0 : _element$ownerDocumen.body);
var win = getWindow(scrollParent);
var target = isBody ? [win].concat(win.visualViewport || [], isScrollParent(scrollParent) ? scrollParent : []) : scrollParent;
var updatedList = list.concat(target);
return isBody ? updatedList : // $FlowFixMe[incompatible-call]: isBody tells us target will be an HTMLElement here
updatedList.concat(listScrollParents(getParentNode(target)));
}