1 #![warn(rust_2018_idioms)]
2 #![cfg(feature = "full")]
3
4 use tokio::io::{AsyncRead, AsyncReadExt, ReadBuf};
5 use tokio_test::assert_ok;
6
7 use std::io;
8 use std::pin::Pin;
9 use std::task::{Context, Poll};
10
11 #[tokio::test]
read()12 async fn read() {
13 #[derive(Default)]
14 struct Rd {
15 poll_cnt: usize,
16 }
17
18 impl AsyncRead for Rd {
19 fn poll_read(
20 mut self: Pin<&mut Self>,
21 _cx: &mut Context<'_>,
22 buf: &mut ReadBuf<'_>,
23 ) -> Poll<io::Result<()>> {
24 assert_eq!(0, self.poll_cnt);
25 self.poll_cnt += 1;
26
27 buf.put_slice(b"hello world");
28 Poll::Ready(Ok(()))
29 }
30 }
31
32 let mut buf = Box::new([0; 11]);
33 let mut rd = Rd::default();
34
35 let n = assert_ok!(rd.read(&mut buf[..]).await);
36 assert_eq!(n, 11);
37 assert_eq!(buf[..], b"hello world"[..]);
38 }
39
40 struct BadAsyncRead;
41
42 impl AsyncRead for BadAsyncRead {
poll_read( self: Pin<&mut Self>, _cx: &mut Context<'_>, buf: &mut ReadBuf<'_>, ) -> Poll<io::Result<()>>43 fn poll_read(
44 self: Pin<&mut Self>,
45 _cx: &mut Context<'_>,
46 buf: &mut ReadBuf<'_>,
47 ) -> Poll<io::Result<()>> {
48 *buf = ReadBuf::new(Box::leak(vec![0; buf.capacity()].into_boxed_slice()));
49 buf.advance(buf.capacity());
50 Poll::Ready(Ok(()))
51 }
52 }
53
54 #[tokio::test]
55 #[should_panic]
read_buf_bad_async_read()56 async fn read_buf_bad_async_read() {
57 let mut buf = Vec::with_capacity(10);
58 BadAsyncRead.read_buf(&mut buf).await.unwrap();
59 }
60