ErrorEvent + onerror, ErrorEvent preventing default

Result: `window.onerror` still fires anyway

by James Greene

JavaScript

if (typeof window.ErrorEvent !== "undefined") {
    window.addEventListener("error", function(e) {
        document.body.innerHTML += "<div>ErrorEvent</div>";

        // Will this prevent `window.onerror` from firing?
        e.stopPropgatation();        
        e.preventDefault();
        return true;
    });
}
else {
    document.body.innerHTML += "<div>ErrorEvent not available in this browser</div>";
}

window.onerror = function() {
    document.body.innerHTML += "<div>onerror</div>";
}

throw new Error("WAT");