1 files changed, 48 insertions, 0 deletions
diff --git a/src/tools/clippy/tests/ui/unused_async.rs b/src/tools/clippy/tests/ui/unused_async.rs
new file mode 100644
index 000000000..4ca7f29b3
--- /dev/null
+++ b/src/tools/clippy/tests/ui/unused_async.rs
@@ -0,0 +1,48 @@
+#![warn(clippy::unused_async)]
+
+use std::future::Future;
+use std::pin::Pin;
+
+async fn foo() -> i32 {
+    4
+}
+
+async fn bar() -> i32 {
+    foo().await
+}
+
+struct S;
+
+impl S {
+    async fn unused(&self) -> i32 {
+        1
+    }
+
+    async fn used(&self) -> i32 {
+        self.unused().await
+    }
+}
+
+trait AsyncTrait {
+    fn trait_method() -> Pin<Box<dyn Future<Output = i32>>>;
+}
+
+macro_rules! async_trait_impl {
+    () => {
+        impl AsyncTrait for S {
+            fn trait_method() -> Pin<Box<dyn Future<Output = i32>>> {
+                async fn unused() -> i32 {
+                    5
+                }
+
+                Box::pin(unused())
+            }
+        }
+    };
+}
+async_trait_impl!();
+
+fn main() {
+    foo();
+    bar();
+}