fn async_failure()

in bindings/rust/extended/s2n-tls/src/callbacks/pkey.rs [313:363]
46 lines of code
4 McCabe index (conditional complexity)

    fn async_failure() -> Result<(), Error> {
        const POLL_COUNT: usize = 10;
        const ERROR: &str = "async_failure error";

        struct TestPkeyFuture {
            counter: usize,
            _op: PrivateKeyOperation,
        }
        impl ConnectionFuture for TestPkeyFuture {
            fn poll(
                mut self: Pin<&mut Self>,
                _conn: &mut connection::Connection,
                ctx: &mut core::task::Context,
            ) -> Poll<Result<(), error::Error>> {
                ctx.waker().wake_by_ref();
                self.counter += 1;
                if self.counter < POLL_COUNT {
                    Poll::Pending
                } else {
                    Poll::Ready(Err(testing::test_error(ERROR)))
                }
            }
        }

        struct TestPkeyCallback(Counter);
        impl PrivateKeyCallback for TestPkeyCallback {
            fn handle_operation(
                &self,
                _conn: &mut connection::Connection,
                _op: PrivateKeyOperation,
            ) -> Result<Option<Pin<Box<dyn ConnectionFuture>>>, error::Error> {
                self.0.increment();
                let future = TestPkeyFuture { counter: 0, _op };
                Ok(Some(Box::pin(future)))
            }
        }

        let (waker, wake_count) = new_count_waker();
        let counter = testing::Counter::default();
        let callback = TestPkeyCallback(counter.clone());
        let mut pair = new_pair(callback, waker)?;

        assert_eq!(counter.count(), 0);
        assert_eq!(wake_count, 0);
        let err = pair.handshake().unwrap_err();
        assert_eq!(counter.count(), 1);
        assert_eq!(wake_count, POLL_COUNT);

        assert_test_error(err, ERROR);
        Ok(())
    }