1 files changed, 148 insertions, 0 deletions
diff --git a/third_party/rust/tokio/tests/io_async_read.rs b/third_party/rust/tokio/tests/io_async_read.rs
new file mode 100644
index 0000000000..20440bbde3
--- /dev/null
+++ b/third_party/rust/tokio/tests/io_async_read.rs
@@ -0,0 +1,148 @@
+#![allow(clippy::transmute_ptr_to_ptr)]
+#![warn(rust_2018_idioms)]
+#![cfg(feature = "full")]
+
+use tokio::io::AsyncRead;
+use tokio_test::task;
+use tokio_test::{assert_ready_err, assert_ready_ok};
+
+use bytes::{BufMut, BytesMut};
+use std::io;
+use std::mem::MaybeUninit;
+use std::pin::Pin;
+use std::task::{Context, Poll};
+
+#[test]
+fn assert_obj_safe() {
+    fn _assert<T>() {}
+    _assert::<Box<dyn AsyncRead>>();
+}
+
+#[test]
+fn read_buf_success() {
+    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 = BytesMut::with_capacity(65);
+
+    task::spawn(Rd).enter(|cx, rd| {
+        let n = assert_ready_ok!(rd.poll_read_buf(cx, &mut buf));
+
+        assert_eq!(11, n);
+        assert_eq!(buf[..], b"hello world"[..]);
+    });
+}
+
+#[test]
+fn read_buf_error() {
+    struct Rd;
+
+    impl AsyncRead for Rd {
+        fn poll_read(
+            self: Pin<&mut Self>,
+            _cx: &mut Context<'_>,
+            _buf: &mut [u8],
+        ) -> Poll<io::Result<usize>> {
+            let err = io::ErrorKind::Other.into();
+            Poll::Ready(Err(err))
+        }
+    }
+
+    let mut buf = BytesMut::with_capacity(65);
+
+    task::spawn(Rd).enter(|cx, rd| {
+        let err = assert_ready_err!(rd.poll_read_buf(cx, &mut buf));
+        assert_eq!(err.kind(), io::ErrorKind::Other);
+    });
+}
+
+#[test]
+fn read_buf_no_capacity() {
+    struct Rd;
+
+    impl AsyncRead for Rd {
+        fn poll_read(
+            self: Pin<&mut Self>,
+            _cx: &mut Context<'_>,
+            _buf: &mut [u8],
+        ) -> Poll<io::Result<usize>> {
+            unimplemented!();
+        }
+    }
+
+    let mut buf = [0u8; 0];
+
+    task::spawn(Rd).enter(|cx, rd| {
+        let n = assert_ready_ok!(rd.poll_read_buf(cx, &mut &mut buf[..]));
+        assert_eq!(0, n);
+    });
+}
+
+#[test]
+fn read_buf_no_uninitialized() {
+    struct Rd;
+
+    impl AsyncRead for Rd {
+        fn poll_read(
+            self: Pin<&mut Self>,
+            _cx: &mut Context<'_>,
+            buf: &mut [u8],
+        ) -> Poll<io::Result<usize>> {
+            for b in buf {
+                assert_eq!(0, *b);
+            }
+
+            Poll::Ready(Ok(0))
+        }
+    }
+
+    let mut buf = BytesMut::with_capacity(64);
+
+    task::spawn(Rd).enter(|cx, rd| {
+        let n = assert_ready_ok!(rd.poll_read_buf(cx, &mut buf));
+        assert_eq!(0, n);
+    });
+}
+
+#[test]
+fn read_buf_uninitialized_ok() {
+    struct Rd;
+
+    impl AsyncRead for Rd {
+        unsafe fn prepare_uninitialized_buffer(&self, _: &mut [MaybeUninit<u8>]) -> bool {
+            false
+        }
+
+        fn poll_read(
+            self: Pin<&mut Self>,
+            _cx: &mut Context<'_>,
+            buf: &mut [u8],
+        ) -> Poll<io::Result<usize>> {
+            assert_eq!(buf[0..11], b"hello world"[..]);
+            Poll::Ready(Ok(0))
+        }
+    }
+
+    // Can't create BytesMut w/ zero capacity, so fill it up
+    let mut buf = BytesMut::with_capacity(64);
+
+    unsafe {
+        let b: &mut [u8] = std::mem::transmute(buf.bytes_mut());
+        b[0..11].copy_from_slice(b"hello world");
+    }
+
+    task::spawn(Rd).enter(|cx, rd| {
+        let n = assert_ready_ok!(rd.poll_read_buf(cx, &mut buf));
+        assert_eq!(0, n);
+    });
+}