How to use run-script argument in pdfkit (wkhtmltopdf python wrapper)

Question

I'm using pdfkit like this: options = { 'run-script': script }

script

    function isOverflown(element) {
        return element.scrollHeight > element.clientHeight
    }

    var els = document.getElementsByClassName('headings');
    for (var i = 0; i < els.length; i++) {
        var el = els[i]
        el.style.height = isOverflown(el) ? '0px' : '300px'
    }

pdfkit.from_file('test.html', options=options)

Has anyone had any success using the run-script argument within pdfkit? I couldn't even get the debug-javascript argument to work either, I tried values of '', True, and 'true'.