[−][src]Trait futures_test::io::AsyncReadTestExt

pub trait AsyncReadTestExt: AsyncRead {
    fn interleave_pending(self) -> InterleavePending<Self>
    where
        Self: Sized,
    { ... }
}

Additional combinators for testing async readers.

Provided methods

fn interleave_pending(self) -> InterleavePending<Self> where
    Self: Sized, 

Introduces an extra Poll::Pending in between each read of the reader.

Examples

#![feature(async_await)]
use futures::task::Poll;
use futures::io::AsyncRead;
use futures_test::task::noop_context;
use futures_test::io::AsyncReadTestExt;
use pin_utils::pin_mut;

let reader = std::io::Cursor::new(&[1, 2, 3]).interleave_pending();
pin_mut!(reader);

let mut cx = noop_context();

let mut buf = [0, 0];

assert_eq!(reader.as_mut().poll_read(&mut cx, &mut buf[..])?, Poll::Pending);
assert_eq!(reader.as_mut().poll_read(&mut cx, &mut buf[..])?, Poll::Ready(2));
assert_eq!(buf, [1, 2]);
assert_eq!(reader.as_mut().poll_read(&mut cx, &mut buf[..])?, Poll::Pending);
assert_eq!(reader.as_mut().poll_read(&mut cx, &mut buf[..])?, Poll::Ready(1));
assert_eq!(buf, [3, 2]);
assert_eq!(reader.as_mut().poll_read(&mut cx, &mut buf[..])?, Poll::Pending);
assert_eq!(reader.as_mut().poll_read(&mut cx, &mut buf[..])?, Poll::Ready(0));

AsyncBufRead

The returned reader will also implement AsyncBufRead if the underlying reader does.

#![feature(async_await)]
use futures::task::Poll;
use futures::io::AsyncBufRead;
use futures_test::task::noop_context;
use futures_test::io::AsyncReadTestExt;
use pin_utils::pin_mut;

let reader = std::io::Cursor::new(&[1, 2, 3]).interleave_pending();
pin_mut!(reader);

let mut cx = noop_context();

assert_eq!(reader.as_mut().poll_fill_buf(&mut cx)?, Poll::Pending);
assert_eq!(reader.as_mut().poll_fill_buf(&mut cx)?, Poll::Ready(&[1, 2, 3][..]));
reader.as_mut().consume(2);
assert_eq!(reader.as_mut().poll_fill_buf(&mut cx)?, Poll::Pending);
assert_eq!(reader.as_mut().poll_fill_buf(&mut cx)?, Poll::Ready(&[3][..]));
reader.as_mut().consume(1);
assert_eq!(reader.as_mut().poll_fill_buf(&mut cx)?, Poll::Pending);
assert_eq!(reader.as_mut().poll_fill_buf(&mut cx)?, Poll::Ready(&[][..]));
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Implementors

impl<R> AsyncReadTestExt for R where
    R: AsyncRead, [src]

fn interleave_pending(self) -> InterleavePending<Self> where
    Self: Sized, [src]

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