chore: checkpoint before Python removal

vendor/futures/tests/future_try_join_all.rs

@@ -0,0 +1,44 @@
+use futures::executor::block_on;
+use futures::future::{err, ok, try_join_all, Future, TryJoinAll};
+use std::fmt::Debug;
+use std::pin::pin;
+
+#[track_caller]
+fn assert_done<T>(actual_fut: impl Future<Output = T>, expected: T)
+where
+    T: PartialEq + Debug,
+{
+    let output = block_on(pin!(actual_fut));
+    assert_eq!(output, expected);
+}
+
+#[test]
+fn collect_collects() {
+    assert_done(try_join_all(vec![ok(1), ok(2)]), Ok::<_, usize>(vec![1, 2]));
+    assert_done(try_join_all(vec![ok(1), err(2)]), Err(2));
+    assert_done(try_join_all(vec![ok(1)]), Ok::<_, usize>(vec![1]));
+    // REVIEW: should this be implemented?
+    // assert_done(try_join_all(Vec::<i32>::new()), Ok(vec![]));
+
+    // TODO: needs more tests
+}
+
+#[test]
+fn try_join_all_iter_lifetime() {
+    // In futures-rs version 0.1, this function would fail to typecheck due to an overly
+    // conservative type parameterization of `TryJoinAll`.
+    fn sizes(bufs: Vec<&[u8]>) -> impl Future<Output = Result<Vec<usize>, ()>> {
+        let iter = bufs.into_iter().map(|b| ok::<usize, ()>(b.len()));
+        try_join_all(iter)
+    }
+
+    assert_done(sizes(vec![&[1, 2, 3], &[], &[0]]), Ok(vec![3_usize, 0, 1]));
+}
+
+#[test]
+fn try_join_all_from_iter() {
+    assert_done(
+        vec![ok(1), ok(2)].into_iter().collect::<TryJoinAll<_>>(),
+        Ok::<_, usize>(vec![1, 2]),
+    )
+}