Trait StreamTestExt

pub trait StreamTestExt: Stream {
    // Provided methods
    fn assert_unmoved(self) -> AssertUnmoved<Self> 
       where Self: Sized { ... }
    fn interleave_pending(self) -> InterleavePending<Self> 
       where Self: Sized { ... }
}

Additional combinators for testing streams.

Provided Methods

fn assert_unmoved(self) -> AssertUnmoved<Self>

where Self: Sized,

Asserts that the given is not moved after being polled.

A check for movement is performed each time the stream is polled and when Drop is called.

Aside from keeping track of the location at which the stream was first polled and providing assertions, this stream adds no runtime behavior and simply delegates to the child stream.

fn interleave_pending(self) -> InterleavePending<Self>

where Self: Sized,

Introduces an extra Poll::Pending in between each item of the stream.

Examples

use futures::task::Poll;
use futures::stream::{self, Stream};
use futures_test::task::noop_context;
use futures_test::stream::StreamTestExt;
use futures::pin_mut;

let stream = stream::iter(vec![1, 2]).interleave_pending();
pin_mut!(stream);

let mut cx = noop_context();

assert_eq!(stream.as_mut().poll_next(&mut cx), Poll::Pending);
assert_eq!(stream.as_mut().poll_next(&mut cx), Poll::Ready(Some(1)));
assert_eq!(stream.as_mut().poll_next(&mut cx), Poll::Pending);
assert_eq!(stream.as_mut().poll_next(&mut cx), Poll::Ready(Some(2)));
assert_eq!(stream.as_mut().poll_next(&mut cx), Poll::Pending);
assert_eq!(stream.as_mut().poll_next(&mut cx), Poll::Ready(None));

Implementors

impl<St> StreamTestExt for St

where St: Stream,