#![warn(rust_2018_idioms)] #![cfg(feature = "full")] use tokio::io::AsyncReadExt; use tokio::net::TcpStream; use tokio_test::assert_ok; use std::thread; use std::{convert::TryInto, io::Write, net}; #[tokio::test] async fn peek() { let listener = net::TcpListener::bind("127.0.0.1:0").unwrap(); let addr = listener.local_addr().unwrap(); let t = thread::spawn(move || assert_ok!(listener.accept()).0); let left = net::TcpStream::connect(&addr).unwrap(); let mut right = t.join().unwrap(); let _ = right.write(&[1, 2, 3, 4]).unwrap(); let mut left: TcpStream = left.try_into().unwrap(); let mut buf = [0u8; 16]; let n = assert_ok!(left.peek(&mut buf).await); assert_eq!([1, 2, 3, 4], buf[..n]); let n = assert_ok!(left.read(&mut buf).await); assert_eq!([1, 2, 3, 4], buf[..n]); }