1 #![warn(rust_2018_idioms)]
2 #![cfg(feature = "full")]
3 
4 use tokio::io::{AsyncWrite, AsyncWriteExt};
5 
6 use std::io;
7 use std::pin::Pin;
8 use std::task::{Context, Poll};
9 
10 #[tokio::test]
write_int_should_err_if_write_count_0()11 async fn write_int_should_err_if_write_count_0() {
12     struct Wr {}
13 
14     impl AsyncWrite for Wr {
15         fn poll_write(
16             self: Pin<&mut Self>,
17             _cx: &mut Context<'_>,
18             _buf: &[u8],
19         ) -> Poll<io::Result<usize>> {
20             Ok(0).into()
21         }
22 
23         fn poll_flush(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<io::Result<()>> {
24             Ok(()).into()
25         }
26 
27         fn poll_shutdown(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<io::Result<()>> {
28             Ok(()).into()
29         }
30     }
31 
32     let mut wr = Wr {};
33 
34     // should be ok just to test these 2, other cases actually expanded by same macro.
35     assert!(wr.write_i8(0).await.is_err());
36     assert!(wr.write_i32(12).await.is_err());
37 }
38