1 files changed, 24 insertions, 5 deletions
diff --git a/src/test/ui/lint/unused/unused-async.rs b/src/test/ui/lint/unused/unused-async.rs
index 7d17af115..4be93aa15 100644
--- a/src/test/ui/lint/unused/unused-async.rs
+++ b/src/test/ui/lint/unused/unused-async.rs
@@ -1,24 +1,43 @@
 // edition:2018
-// run-pass
-#![allow(dead_code)]
+#![deny(unused_must_use)]
+
 
 #[must_use]
-//~^ WARNING `must_use`
-async fn test() -> i32 {
+async fn foo() -> i32 {
     1
 }
 
+#[must_use]
+fn bar() -> impl std::future::Future<Output=i32> {
+    async {
+        42
+    }
+}
+
+async fn baz() -> i32 {
+    0
+}
 
 struct Wowee {}
 
 impl Wowee {
     #[must_use]
-    //~^ WARNING `must_use`
     async fn test_method() -> i32 {
         1
     }
 }
 
+async fn test() {
+    foo(); //~ ERROR unused return value of `foo` that must be used
+    //~^ ERROR unused implementer of `Future` that must be used
+    foo().await; //~ ERROR unused output of future returned by `foo` that must be used
+    bar(); //~ ERROR unused return value of `bar` that must be used
+    //~^ ERROR unused implementer of `Future` that must be used
+    bar().await; //~ ERROR unused output of future returned by `bar` that must be used
+    baz(); //~ ERROR unused implementer of `Future` that must be used
+    baz().await; // ok
+}
+
 /* FIXME(guswynn) update this test when async-fn-in-traits works
 trait Doer {
     #[must_use]