futures: tests/try_join_all.rs: Don't break w/o "executor"

- Symbols/Imports pushed down / localised
- Tests gated with cfg()
- Tests now build and pass with all valid feature combinations

See previous commits for details and rationale

Author: kentfredric

futures/tests/try_join_all.rs

@@ -1,19 +1,26 @@
-use futures_util::future::*;
-use std::future::Future;
-use futures::executor::block_on;
-use std::fmt::Debug;
-
-fn assert_done<T, F>(actual_fut: F, expected: T)
-where
-    T: PartialEq + Debug,
-    F: FnOnce() -> Box<dyn Future<Output = T> + Unpin>,
-{
-    let output = block_on(actual_fut());
-    assert_eq!(output, expected);
+#[cfg(feature = "executor")] // executor::
+mod util {
+    use std::future::Future;
+    use futures::executor::block_on;
+    use std::fmt::Debug;
+
+    pub fn assert_done<T, F>(actual_fut: F, expected: T)
+    where
+        T: PartialEq + Debug,
+        F: FnOnce() -> Box<dyn Future<Output = T> + Unpin>,
+    {
+        let output = block_on(actual_fut());
+        assert_eq!(output, expected);
+    }
 }
 
+#[cfg(feature = "executor")] // assert_done
 #[test]
 fn collect_collects() {
+    use futures_util::future::{err, ok, try_join_all};
+
+    use util::assert_done;
+
     assert_done(|| Box::new(try_join_all(vec![ok(1), ok(2)])), Ok::<_, usize>(vec![1, 2]));
     assert_done(|| Box::new(try_join_all(vec![ok(1), err(2)])), Err(2));
     assert_done(|| Box::new(try_join_all(vec![ok(1)])), Ok::<_, usize>(vec![1]));
@@ -23,8 +30,14 @@ fn collect_collects() {
     // TODO: needs more tests
 }
 
+#[cfg(feature = "executor")] // assert_done
 #[test]
 fn try_join_all_iter_lifetime() {
+    use futures_util::future::{ok, try_join_all};
+    use std::future::Future;
+
+    use util::assert_done;
+
     // In futures-rs version 0.1, this function would fail to typecheck due to an overly
     // conservative type parameterization of `TryJoinAll`.
     fn sizes<'a>(bufs: Vec<&'a [u8]>) -> Box<dyn Future<Output = Result<Vec<usize>, ()>> + Unpin> {
@@ -35,8 +48,13 @@ fn try_join_all_iter_lifetime() {
     assert_done(|| sizes(vec![&[1,2,3], &[], &[0]]), Ok(vec![3 as usize, 0, 1]));
 }
 
+#[cfg(feature = "executor")] // assert_done
 #[test]
 fn try_join_all_from_iter() {
+    use futures_util::future::{ok, TryJoinAll};
+
+    use util::assert_done;
+
     assert_done(
         || Box::new(vec![ok(1), ok(2)].into_iter().collect::<TryJoinAll<_>>()),
         Ok::<_, usize>(vec![1, 2]),