1 | use futures::executor::block_on; |
2 | use futures::pin_mut; |
3 | use futures::stream::{self, Peekable, StreamExt}; |
4 | |
5 | #[test] |
6 | fn peekable() { |
7 | block_on(async { |
8 | let peekable: Peekable<_> = stream::iter(vec![1u8, 2, 3]).peekable(); |
9 | pin_mut!(peekable); |
10 | assert_eq!(peekable.as_mut().peek().await, Some(&1u8)); |
11 | assert_eq!(peekable.collect::<Vec<u8>>().await, vec![1, 2, 3]); |
12 | |
13 | let s = stream::once(async { 1 }).peekable(); |
14 | pin_mut!(s); |
15 | assert_eq!(s.as_mut().peek().await, Some(&1u8)); |
16 | assert_eq!(s.collect::<Vec<u8>>().await, vec![1]); |
17 | }); |
18 | } |
19 | |
20 | #[test] |
21 | fn peekable_mut() { |
22 | block_on(async { |
23 | let s = stream::iter(vec![1u8, 2, 3]).peekable(); |
24 | pin_mut!(s); |
25 | if let Some(p) = s.as_mut().peek_mut().await { |
26 | if *p == 1 { |
27 | *p = 5; |
28 | } |
29 | } |
30 | assert_eq!(s.collect::<Vec<_>>().await, vec![5, 2, 3]); |
31 | }); |
32 | } |
33 | |
34 | #[test] |
35 | fn peekable_next_if_eq() { |
36 | block_on(async { |
37 | // first, try on references |
38 | let s = stream::iter(vec!["Heart" , "of" , "Gold" ]).peekable(); |
39 | pin_mut!(s); |
40 | // try before `peek()` |
41 | assert_eq!(s.as_mut().next_if_eq(&"trillian" ).await, None); |
42 | assert_eq!(s.as_mut().next_if_eq(&"Heart" ).await, Some("Heart" )); |
43 | // try after peek() |
44 | assert_eq!(s.as_mut().peek().await, Some(&"of" )); |
45 | assert_eq!(s.as_mut().next_if_eq(&"of" ).await, Some("of" )); |
46 | assert_eq!(s.as_mut().next_if_eq(&"zaphod" ).await, None); |
47 | // make sure `next()` still behaves |
48 | assert_eq!(s.next().await, Some("Gold" )); |
49 | |
50 | // make sure comparison works for owned values |
51 | let s = stream::iter(vec![String::from("Ludicrous" ), "speed" .into()]).peekable(); |
52 | pin_mut!(s); |
53 | // make sure basic functionality works |
54 | assert_eq!(s.as_mut().next_if_eq("Ludicrous" ).await, Some("Ludicrous" .into())); |
55 | assert_eq!(s.as_mut().next_if_eq("speed" ).await, Some("speed" .into())); |
56 | assert_eq!(s.as_mut().next_if_eq("" ).await, None); |
57 | }); |
58 | } |
59 | |