1use futures::executor::block_on;
2use futures::future::{join_all, ready, Future, JoinAll};
3use futures::pin_mut;
4use std::fmt::Debug;
5
6#[track_caller]
7fn assert_done<T>(actual_fut: impl Future<Output = T>, expected: T)
8where
9 T: PartialEq + Debug,
10{
11 pin_mut!(actual_fut);
12 let output = block_on(actual_fut);
13 assert_eq!(output, expected);
14}
15
16#[test]
17fn collect_collects() {
18 assert_done(join_all(vec![ready(1), ready(2)]), vec![1, 2]);
19 assert_done(join_all(vec![ready(1)]), vec![1]);
20 // REVIEW: should this be implemented?
21 // assert_done(join_all(Vec::<i32>::new()), vec![]);
22
23 // TODO: needs more tests
24}
25
26#[test]
27fn join_all_iter_lifetime() {
28 // In futures-rs version 0.1, this function would fail to typecheck due to an overly
29 // conservative type parameterization of `JoinAll`.
30 fn sizes(bufs: Vec<&[u8]>) -> impl Future<Output = Vec<usize>> {
31 let iter = bufs.into_iter().map(|b| ready::<usize>(b.len()));
32 join_all(iter)
33 }
34
35 assert_done(sizes(vec![&[1, 2, 3], &[], &[0]]), vec![3_usize, 0, 1]);
36}
37
38#[test]
39fn join_all_from_iter() {
40 assert_done(vec![ready(1), ready(2)].into_iter().collect::<JoinAll<_>>(), vec![1, 2])
41}
42