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use futures::executor::block_on;
use futures::future::{self, FusedFuture, FutureExt};
use futures::select;
use futures::stream::{FuturesUnordered, StreamExt};
use futures::task::{Context, Poll};
use futures_test::future::FutureTestExt;
use futures_test::task::new_count_waker;
#[test]
fn is_terminated() {
let (waker, counter) = new_count_waker();
let mut cx = Context::from_waker(&waker);
let mut tasks = FuturesUnordered::new();
let mut select_next_some = tasks.select_next_some();
assert_eq!(select_next_some.is_terminated(), false);
assert_eq!(select_next_some.poll_unpin(&mut cx), Poll::Pending);
assert_eq!(counter, 1);
assert_eq!(select_next_some.is_terminated(), true);
drop(select_next_some);
tasks.push(future::ready(1));
let mut select_next_some = tasks.select_next_some();
assert_eq!(select_next_some.is_terminated(), false);
assert_eq!(select_next_some.poll_unpin(&mut cx), Poll::Ready(1));
assert_eq!(select_next_some.is_terminated(), false);
assert_eq!(select_next_some.poll_unpin(&mut cx), Poll::Pending);
assert_eq!(select_next_some.is_terminated(), true);
}
#[test]
fn select() {
// Checks that even though `async_tasks` will yield a `None` and return
// `is_terminated() == true` during the first poll, it manages to toggle
// back to having items after a future is pushed into it during the second
// poll (after pending_once completes).
block_on(async {
let mut fut = future::ready(1).pending_once();
let mut async_tasks = FuturesUnordered::new();
let mut total = 0;
loop {
select! {
num = fut => {
total += num;
async_tasks.push(async { 5 });
},
num = async_tasks.select_next_some() => {
total += num;
}
complete => break,
}
}
assert_eq!(total, 6);
});
}
// Check that `select!` macro does not fail when importing from `futures_util`.
#[test]
fn futures_util_select() {
use futures_util::select;
// Checks that even though `async_tasks` will yield a `None` and return
// `is_terminated() == true` during the first poll, it manages to toggle
// back to having items after a future is pushed into it during the second
// poll (after pending_once completes).
block_on(async {
let mut fut = future::ready(1).pending_once();
let mut async_tasks = FuturesUnordered::new();
let mut total = 0;
loop {
select! {
num = fut => {
total += num;
async_tasks.push(async { 5 });
},
num = async_tasks.select_next_some() => {
total += num;
}
complete => break,
}
}
assert_eq!(total, 6);
});
}