composition select_second

src/func/instances/composition.rs

@@ -181,9 +181,9 @@ impl<'a, U: SharedFunctor<'a> + Functor<'a>, V: SharedFunctor<'a>> SharedFunctor
 mod composition_tests {
     use std::sync::Arc;
 
-    use crate::func::instances::{option::OptionInstance, result::ResultInstance};
+    use crate::func::instances::{option::*, result::*, tryfuture::TryFutureInstance};
 
-    use super::{test_suite, tests, CompositionInstance};
+    use super::*;
 
     type T = CompositionInstance<OptionInstance, ResultInstance<i32>>;
 
@@ -219,4 +219,17 @@ mod composition_tests {
     fn shared_follows_laws() {
         test_suite::shared_follows_laws::<T>().unwrap();
     }
+
+    #[test]
+    fn select_second() {
+        type T = CompositionInstance<TryFutureInstance<i32>, ResultInstance<i32>>;
+
+        let res = futures::executor::block_on(T::select(
+            Box::pin(futures::future::pending::<Result<Result<i32, i32>, i32>>()),
+            Box::pin(futures::future::ready(Ok(Ok(2)))),
+        ))
+        .unwrap()
+        .unwrap();
+        assert!(matches!(res, Selected::B(_, 2)));
+    }
 }