add new spawn sig tests

actix-rt/CHANGES.md

@@ -1,6 +1,9 @@
 # Changes
 
 ## Unreleased - 2021-xx-xx
+* The `spawn` method can now resolve with non-unit outputs. [#369]
+
+[#369]: https://github.com/actix/actix-net/pull/369
 
 
 ## 2.2.0 - 2021-03-29

actix-rt/tests/tests.rs

@@ -9,6 +9,7 @@ use std::{
 };
 
 use actix_rt::{Arbiter, System};
+use futures_core::Future;
 use tokio::sync::oneshot;
 
 #[test]
@@ -298,3 +299,26 @@ fn try_current_no_system() {
 fn try_current_with_system() {
     System::new().block_on(async { assert!(System::try_current().is_some()) });
 }
+
+#[actix_rt::test]
+async fn spawn_local() {
+    // demonstrate that spawn -> R is strictly more capable than spawn -> ()
+
+    assert_eq!(actix_rt::spawn(async { (|| {})() }).await.unwrap(), ());
+    assert_eq!(actix_rt::spawn(async { 1 }).await.unwrap(), 1);
+    assert!(actix_rt::spawn(async { panic!("") }).await.is_err());
+
+    actix_rt::spawn(async { tokio::time::sleep(Duration::from_millis(50)).await })
+        .await
+        .unwrap();
+
+    use actix_rt::task::JoinError;
+
+    fn g<F: Future<Output = Result<(), JoinError>>>(_f: F) {}
+    g(actix_rt::spawn(async {}));
+    // g(actix_rt::spawn(async { 1 })); // compile err
+
+    fn h<F: Future<Output = Result<R, JoinError>>, R>(_f: F) {}
+    h(actix_rt::spawn(async {}));
+    h(actix_rt::spawn(async { 1 }));
+}