1use futures_task::{FutureObj, Spawn, SpawnError};
2use std::cell::{Ref, RefCell};
3
4/// An implementation of [`Spawn`](futures_task::Spawn) that records
5/// any [`Future`](futures_core::future::Future)s spawned on it.
6///
7/// # Examples
8///
9/// ```
10/// use futures::task::SpawnExt;
11/// use futures_test::task::RecordSpawner;
12///
13/// let recorder = RecordSpawner::new();
14/// recorder.spawn(async { }).unwrap();
15/// assert_eq!(recorder.spawned().len(), 1);
16/// ```
17#[derive(Debug, Default)]
18pub struct RecordSpawner {
19 spawned: RefCell<Vec<FutureObj<'static, ()>>>,
20}
21
22impl RecordSpawner {
23 /// Create a new instance
24 pub fn new() -> Self {
25 Default::default()
26 }
27
28 /// Inspect any futures that were spawned onto this [`Spawn`].
29 pub fn spawned(&self) -> Ref<'_, Vec<FutureObj<'static, ()>>> {
30 self.spawned.borrow()
31 }
32}
33
34impl Spawn for RecordSpawner {
35 fn spawn_obj(&self, future: FutureObj<'static, ()>) -> Result<(), SpawnError> {
36 self.spawned.borrow_mut().push(future);
37 Ok(())
38 }
39}
40