Problem with jshint

[georgest]

This while (element = element.parentNode) in _elementInDocument function is not accepted by jshint. It shows this error:

Expected a conditional expression and instead saw an assignment.

Can it be done this way:

function _elementInDocument(element) {
    while (true) {
        element = element.parentNode;
        if (element == document) {
            return true;
        }
    }
    return false;
}