/
io_take.rs
44 lines (35 loc) · 968 Bytes
/
io_take.rs
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#![warn(rust_2018_idioms)]
#![cfg(feature = "full")]
use std::pin::Pin;
use std::task::{Context, Poll};
use tokio::io::{self, AsyncRead, AsyncReadExt, ReadBuf};
use tokio_test::assert_ok;
#[tokio::test]
async fn take() {
let mut buf = [0; 6];
let rd: &[u8] = b"hello world";
let mut rd = rd.take(4);
let n = assert_ok!(rd.read(&mut buf).await);
assert_eq!(n, 4);
assert_eq!(&buf, &b"hell\0\0"[..]);
}
struct BadReader;
impl AsyncRead for BadReader {
fn poll_read(
self: Pin<&mut Self>,
_cx: &mut Context<'_>,
read_buf: &mut ReadBuf<'_>,
) -> Poll<io::Result<()>> {
let vec = vec![0; 10];
let mut buf = ReadBuf::new(vec.leak());
buf.put_slice(&[123; 10]);
*read_buf = buf;
Poll::Ready(Ok(()))
}
}
#[tokio::test]
#[should_panic]
async fn bad_reader_fails() {
let mut buf = Vec::with_capacity(10);
BadReader.take(10).read_buf(&mut buf).await.unwrap();
}