3 ms·
Does Node support filtered errors like Bluebird? somePromise.then(function() { return a.b.c.d(); }).catch(TypeError, ReferenceError, function(e) {
by Androider 9y ago
Does Node support filtered errors like Bluebird?
somePromise.then(function() {
return a.b.c.d();
}).catch(TypeError, ReferenceError, function(e) {
//Will end up here on programmer error
}).catch(NetworkError, TimeoutError, function(e) {
//Will end up here on expected everyday network errors
}).catch(function(e) {
//Catch any unexpected errors
});
It's super useful.
- AngelloPozo 9y agoI have not tried, but I would guess no. Why not give it a try and see?
- kkennis 9y agoThe standard way to handle errors coming from 'await' is try/catch, and any errors can be handled in the catch block as if they were coming from a synchronous context. So, you'd now filter async errors the same way you filter synchronous ones.
- Tarean 9y agoLooks really clean. Does bluebird handle this(https://hackage.haskell.org/package/base-4.9.0.0/docs/Control-Exception.html#v:catches https://hackage.haskell.org/package/base-4.9.0.0/docs/Contro...) problem? Sometimes you want to catch two different sorts of exception. You could do something like f = expr `catch` \ (ex :: ArithException) -> handleArith ex `catch` \ (ex :: IOException) -> handleIO ex However, there are a couple of problems with this approach. The first is that having two exception handlers is inefficient. However, the more serious issue is that the second exception handler will catch exceptions in the first, e.g. in the example above, if handleArith throws an IOException then the second exception handler will catch it. Instead, we provide a function catches, which would be used thus: f = expr `catches` [Handler (\ex :: ArithException -> handleArith ex), Handler (\ex :: IOException -> handleIO ex)]
- idbehold 9y agoYes. .catch(ArithException, IOException, handleError) Edit: Nevermind, I think what you want to be able to do is provide two different error handlers, but essentially catch them at the same time so that if you throw inside one of them, the second one wouldn't catch it.
- NoInkling 9y agoNot related to the aforementioned Bluebird feature, but I think that's the very reason the promise spec allows you to specify an error callback as the second argument to .then. I guess you can always fallback to an if/switch statement if it's a concern (which is what you'd do with await and try/catch).
- tkxxx7 9y agothis library does: https://github.com/bigeasy/cadence https://github.com/bigeasy/cadence