I know our program is capable to handle the errors now, but adding a catch method next to the ‘then’ method causes our program to look more beautiful.
In order to implement this method you just need to know one thing.
Let me reveal the secret of the cache method here.
In fact, the catch method is the then method that its first parameter is null. That’s it.
asyncHanlder.catch = function (onError) {
return asyncHanlder.then(null, onError);
}Add this code after the definition of the then method.
Definitely this section is the shortest.