#![warn(rust_2018_idioms)]
#![cfg(feature = "full")]
use tokio::io::{self, AsyncRead, ReadBuf};
use tokio_test::assert_ok;
use std::pin::Pin;
use std::task::{Context, Poll};
#[tokio::test]
async fn copy() {
struct Rd(bool);
impl AsyncRead for Rd {
fn poll_read(
mut self: Pin<&mut Self>,
_cx: &mut Context<'_>,
buf: &mut ReadBuf<'_>,
) -> Poll<io::Result<()>> {
if self.0 {
buf.put_slice(b"hello world");
self.0 = false;
Poll::Ready(Ok(()))
} else {
Poll::Ready(Ok(()))
}
}
}
let mut rd = Rd(true);
let mut wr = Vec::new();
let n = assert_ok!(io::copy(&mut rd, &mut wr).await);
assert_eq!(n, 11);
assert_eq!(wr, b"hello world");
}