iFrame error test

JavaScript

const iframe = document.createElement('iframe');
    iframe.onload = function () {
        try {
            iframe.contentWindow.name;
        } catch (e) {
            if (e.message.includes('cross-origin')) console.warn(e.message);
            else console.error(e);
        }
    }

    iframe.src = "https://google.com";
    document.body.appendChild(iframe);