Future throw exception handle outside from origin future - dart

Question

i am trying to understand, how dart future exception works. I read a very good article about it link. But when i have nested future and the first of them throw an error, how can i handle this error on the second future.
To clarify, what i mean look at the following sample.
import 'dart:async';
void main() {
var fur1 = new Future<int>(() => 45);
fur1.then((value) {
throw new StateError('Hello error');
});
var fur2 = new Future<int>(() => 24);
fur2.then((value) {
fur1.then((value1) {
print(value1);
});
print(value);
}).catchError((err) => print(err));
}
In the fur1, i throw an exception and expected to catch the error in the fur2, but the compiler show message
Unhandled exception: Bad state: Hello error
It is possible to handle nested error in future? I know, i could use here the completer class, maybe it would be the solution?

Answer 1

I'm not sure what you actually try to accomplish.
but for me it works this way
import 'dart:async';
void main() {
var fur1 = new Future<int>(() => 45);
// fur1.then((value) {
// throw new StateError('Hello error');
// });
var fur2 = new Future<int>(() => 24);
fur2.then((value) {
var x = fur1.then((value1) {
print(value1);
throw new StateError('Hello error'); // <= inner exception
});
print(value);
return x; // <= return future
}).catchError((err) => print('catchError: ${err}'));
}
or this way
import 'dart:async';
void main() {
var fur1 = new Future<int>(() => 45);
fur1.then((value) {
throw new StateError('Hello1 error');
}).catchError((err) => print('catchError1: ${err}'));
var fur2 = new Future<int>(() => 24);
fur2.then((value) {
var x = fur1.then((value1) {
print(value1);
throw new StateError('Hello2 error'); // <= inner exception
});
print(value);
return x; // <= return future
}).catchError((err) => print('catchError2: ${err}'));
}
catchError1: Bad state: Hello1 error
24
45
catchError2: Bad state: Hello2 error