tokio: move I/O helpers to ext traits (#1204)

Refs: #1203

1 files changed, 41 insertions, 0 deletions

diff --git a/tokio/tests/io_read.rs b/tokio/tests/io_read.rs
new file mode 100644
index 00000000..8544a6c6
--- /dev/null
+++ b/tokio/tests/io_read.rs
@@ -0,0 +1,41 @@
+#![deny(warnings, rust_2018_idioms)]
+
+use tokio::io::{AsyncRead, AsyncReadExt};
+use tokio_test::assert_ready_ok;
+use tokio_test::task::MockTask;
+
+use pin_utils::pin_mut;
+use std::future::Future;
+use std::io;
+use std::pin::Pin;
+use std::task::{Context, Poll};
+
+#[test]
+fn read() {
+    struct Rd;
+
+    impl AsyncRead for Rd {
+        fn poll_read(
+            self: Pin<&mut Self>,
+            _cx: &mut Context<'_>,
+            buf: &mut [u8],
+        ) -> Poll<io::Result<usize>> {
+            buf[0..11].copy_from_slice(b"hello world");
+            Poll::Ready(Ok(11))
+        }
+    }
+
+    let mut buf = Box::new([0; 11]);
+    let mut task = MockTask::new();
+
+    task.enter(|cx| {
+        let mut rd = Rd;
+
+        let read = rd.read(&mut buf[..]);
+        pin_mut!(read);
+
+        let n = assert_ready_ok!(read.poll(cx));
+        assert_eq!(n, 11);
+        assert_eq!(buf[..], b"hello world"[..]);
+    });
+}