my working clean solution (2017)
function loaderScript(scriptUrl){
return new Promise(function (res, rej) {
let script = document.createElement('script');
script.src = scriptUrl;
script.type = 'text/javascript';
script.onErroronerror = rej;
script.async = true;
script.onload = res;
script.addEventListener('error',rej);
script.addEventListener('load',res);
document.head.appendChild(script);
})
}
As Martin pointed, used like that:
const event = loaderScript("myscript.js")
.then(() => { console.log("loaded"); })
.catch(() => { console.log("error"); });
OR
try{
await loaderScript("myscript.js")
console.log("loaded");
}catch{
console.log("error");
}