keyforkd: add tests for middleware, relax serde service trait bounds

keyforkd/src/middleware.rs

@@ -50,10 +50,10 @@ pub enum SerdeServiceError {
 
 impl<S, Request> Service<Vec<u8>> for SerdeService<S, Request>
 where
-    S: Service<Request> + Send + Sync,
+    S: Service<Request>,
-    Request: DeserializeOwned + Send,
+    Request: DeserializeOwned,
-    <S as Service<Request>>::Error: std::error::Error + Send,
+    <S as Service<Request>>::Response: Serialize,
-    <S as Service<Request>>::Response: Serialize + Send,
+    <S as Service<Request>>::Error: std::error::Error,
     <S as Service<Request>>::Future: Send + 'static,
 {
     type Response = Vec<u8>;
@@ -89,3 +89,45 @@ where
         })
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use serde::{Deserialize, Serialize};
+    use std::{future::Future, pin::Pin, task::Poll};
+    use tower::{ServiceBuilder, ServiceExt};
+
+    #[derive(Serialize, Deserialize)]
+    struct Test {
+        field: String,
+    }
+
+    struct App;
+
+    #[derive(Debug, thiserror::Error)]
+    enum Infallible {}
+
+    impl Service<Test> for App {
+        type Response = Test;
+        type Error = Infallible;
+        type Future = Pin<Box<dyn Future<Output = Result<Self::Response, Self::Error>> + Send>>;
+
+        fn poll_ready(&mut self, _cx: &mut std::task::Context<'_>) -> std::task::Poll<Result<(), Self::Error>> {
+            Poll::Ready(Ok(()))
+        }
+
+        fn call(&mut self, req: Test) -> Self::Future {
+            Box::pin(async { Ok(req) })
+        }
+    }
+
+    #[tokio::test]
+    async fn can_serde_responses() {
+        let content = serialize(&Test { field: "hello world!".to_string() }).unwrap();
+        let mut service = ServiceBuilder::new()
+            .layer(SerdeLayer::<Test>::new())
+            .service(App);
+        let result = service.ready().await.unwrap().call(content.clone()).await.unwrap();
+        assert_eq!(result, content);
+    }
+}