Catching all javascript unhandled exceptions

You can do this by using window.onerror method.

window.onerror = function myErrorHandler(errorMsg, url, lineNumber) {
    alert("Error occured: " + errorMsg);//or any message
    return false;
}

You can either use window.onerror, or (amazingly!) bind to the 'error' event properly:

window.onerror = function (message, file, line, col, error) {
   alert("Error occurred: " + error.message);
   return false;
};
window.addEventListener("error", function (e) {
   alert("Error occurred: " + e.error.message);
   return false;
})

If you want to track JavaScript errors, you can try Atatus. I work at Atatus.