fix: allow missing id and missing params

Cargo.toml

@@ -5,7 +5,7 @@ description = "Simple, modern, ergonomic JSON-RPC 2.0 router built with tower an
 keywords = ["json-rpc", "jsonrpc", "json"]
 categories = ["web-programming::http-server", "web-programming::websocket"]
 
-version = "0.1.1"
+version = "0.1.2"
 edition = "2021"
 rust-version = "1.81"
 authors = ["init4", "James Prestwich"]

src/pubsub/shared.rs

@@ -202,9 +202,12 @@ where
                         break;
                     };
 
-                    let Ok(req) = Request::try_from(item) else {
-                        tracing::warn!("inbound request is malformatted");
-                        continue
+                    let req = match Request::try_from(item) {
+                        Ok(req) => req,
+                        Err(err) => {
+                            tracing::warn!(%err, "inbound request is malformatted");
+                            continue
+                        }
                     };
 
                     let span = debug_span!("ipc request handling", id = req.id(), method = req.method());

src/types/req.rs

@@ -31,7 +31,7 @@ pub struct Request {
     ///
     /// This field is generated by deserializing to a [`RawValue`] and then
     /// calculating the offset of the backing slice within the `bytes` field.
-    id: Range<usize>,
+    id: Option<Range<usize>>,
     /// A range of the `bytes` field that represents the method field of the
     /// JSON-RPC request.
     ///
@@ -49,7 +49,7 @@ pub struct Request {
     ///
     /// This field is generated by deserializing to a [`RawValue`] and then
     /// calculating the offset of the backing slice within the `bytes` field.
-    params: Range<usize>,
+    params: Option<Range<usize>>,
 }
 
 impl core::fmt::Debug for Request {
@@ -67,11 +67,11 @@ impl core::fmt::Debug for Request {
 #[derive(serde::Deserialize)]
 struct DeserHelper<'a> {
     #[serde(borrow)]
-    id: &'a RawValue,
+    id: Option<&'a RawValue>,
     #[serde(borrow)]
     method: &'a RawValue,
     #[serde(borrow)]
-    params: &'a RawValue,
+    params: Option<&'a RawValue>,
 }
 
 impl TryFrom<Bytes> for Request {
@@ -80,12 +80,19 @@ impl TryFrom<Bytes> for Request {
     fn try_from(bytes: Bytes) -> Result<Self, Self::Error> {
         let DeserHelper { id, method, params } = serde_json::from_slice(bytes.as_ref())?;
 
-        let id = find_range!(bytes, id.get());
-        // Ensure the id is not too long
-        let id_len = id.end - id.start;
-        if id_len > ID_LEN_LIMIT {
-            return Err(RequestError::IdTooLarge(id_len));
-        }
+        let id = if let Some(id) = id {
+            let id = find_range!(bytes, id.get());
+
+            // Ensure the id is not too long
+            let id_len = id.end - id.start;
+            if id_len > ID_LEN_LIMIT {
+                return Err(RequestError::IdTooLarge(id_len));
+            }
+
+            Some(id)
+        } else {
+            None
+        };
 
         // Ensure method is a string, and not too long, and trim the quotes
         // from it
@@ -101,7 +108,7 @@ impl TryFrom<Bytes> for Request {
             return Err(RequestError::MethodTooLarge(method_len));
         }
 
-        let params = find_range!(bytes, params.get());
+        let params = params.map(|params| find_range!(bytes, params.get()));
 
         Ok(Self {
             bytes,
@@ -122,11 +129,20 @@ impl TryFrom<tokio_tungstenite::tungstenite::Utf8Bytes> for Request {
 }
 
 impl Request {
-    /// Return a reference to the serialized ID field.
+    /// Return a reference to the serialized ID field. If the ID field is
+    /// missing, this will return `"null"`, ensuring that response correctly
+    /// have a null ID, as per [the JSON-RPC spec].
+    ///
+    /// [the JSON-RPC spec]: https://www.jsonrpc.org/specification#response_object
     pub fn id(&self) -> &str {
-        // SAFETY: `id` is guaranteed to be valid JSON,
-        // and a valid slice of `bytes`.
-        unsafe { core::str::from_utf8_unchecked(self.bytes.get_unchecked(self.id.clone())) }
+        self.id
+            .as_ref()
+            .map(|range| {
+                // SAFETY: `range` is guaranteed to be valid JSON, and a valid
+                // slice of `bytes`.
+                unsafe { core::str::from_utf8_unchecked(self.bytes.get_unchecked(range.clone())) }
+            })
+            .unwrap_or("null")
     }
 
     /// Return an owned version of the serialized ID field.
@@ -161,9 +177,13 @@ impl Request {
 
     /// Return a reference to the serialized params field.
     pub fn params(&self) -> &str {
-        // SAFETY: `params` is guaranteed to be valid JSON,
-        // and a valid slice of `bytes`.
-        unsafe { core::str::from_utf8_unchecked(self.bytes.get_unchecked(self.params.clone())) }
+        if let Some(range) = &self.params {
+            // SAFETY: `range` is guaranteed to be valid JSON, and a valid
+            // slice of `bytes`.
+            unsafe { core::str::from_utf8_unchecked(self.bytes.get_unchecked(range.clone())) }
+        } else {
+            "null"
+        }
     }
 
     /// Deserialize the params field into a type.

tests/common/mod.rs

@@ -28,35 +28,63 @@ pub fn test_router() -> ajj::Router<()> {
 
 /// Test clients
 pub trait TestClient {
-    async fn send<S: serde::Serialize>(&mut self, method: &str, params: &S);
+    fn next_id(&mut self) -> usize;
+
+    async fn send_raw<S: serde::Serialize>(&mut self, msg: &S);
+
     async fn recv<D: serde::de::DeserializeOwned>(&mut self) -> D;
+
+    async fn send<S: serde::Serialize>(&mut self, method: &str, params: &S) -> usize {
+        let id = self.next_id();
+        self.send_raw(&serde_json::json!({
+            "jsonrpc": "2.0",
+            "id": id,
+            "method": method,
+            "params": params,
+        }))
+        .await;
+        id
+    }
 }
 
 /// basic tests of the test router
 pub async fn basic_tests<T: TestClient>(mut client: T) {
-    client.send("ping", &()).await;
+    test_ping(&mut client).await;
 
-    let next: Value = client.recv().await;
-    assert_eq!(
-        next,
-        serde_json::json!({"id": 0, "jsonrpc": "2.0", "result": "pong"})
-    );
+    test_double(&mut client).await;
+
+    test_notify(&mut client).await;
+
+    test_missing_id(&mut client).await;
+}
+
+async fn test_missing_id<T: TestClient>(client: &mut T) {
+    client
+        .send_raw(&serde_json::json!(
+            {"jsonrpc": "2.0", "method": "ping"}
+        ))
+        .await;
 
-    client.send("double", &5).await;
     let next: Value = client.recv().await;
     assert_eq!(
         next,
-        serde_json::json!({"id": 1, "jsonrpc": "2.0", "result": 10})
+        serde_json::json!({
+            "jsonrpc": "2.0",
+            "result": "pong",
+            "id": null,
+        })
     );
+}
 
-    client.send("notify", &()).await;
+async fn test_notify<T: TestClient>(client: &mut T) {
+    let id = client.send("notify", &()).await;
 
     let now = std::time::Instant::now();
 
     let next: Value = client.recv().await;
     assert_eq!(
         next,
-        serde_json::json!({"id": 2, "jsonrpc": "2.0", "result": null})
+        serde_json::json!({"id": id, "jsonrpc": "2.0", "result": null})
     );
 
     let next: Value = client.recv().await;
@@ -66,3 +94,22 @@ pub async fn basic_tests<T: TestClient>(mut client: T) {
         serde_json::json!({"method": "notify", "result": "notified"})
     );
 }
+
+async fn test_double<T: TestClient>(client: &mut T) {
+    let id = client.send("double", &5).await;
+    let next: Value = client.recv().await;
+    assert_eq!(
+        next,
+        serde_json::json!({"id": id, "jsonrpc": "2.0", "result": 10})
+    );
+}
+
+async fn test_ping<T: TestClient>(client: &mut T) {
+    let id = client.send("ping", &()).await;
+
+    let next: Value = client.recv().await;
+    assert_eq!(
+        next,
+        serde_json::json!({"id": id, "jsonrpc": "2.0", "result": "pong"})
+    );
+}

tests/ipc.rs

@@ -64,24 +64,17 @@ impl IpcClient {
     async fn recv_inner(&mut self) -> serde_json::Value {
         self.recv_half.next().await.unwrap()
     }
+}
 
+impl TestClient for IpcClient {
     fn next_id(&mut self) -> usize {
         let id = self.id;
         self.id += 1;
         id
     }
-}
 
-impl TestClient for IpcClient {
-    async fn send<S: serde::Serialize>(&mut self, method: &str, params: &S) {
-        let id = self.next_id();
-        self.send_inner(&serde_json::json!({
-            "jsonrpc": "2.0",
-            "id": id,
-            "method": method,
-            "params": params,
-        }))
-        .await;
+    async fn send_raw<S: serde::Serialize>(&mut self, msg: &S) {
+        self.send_inner(msg).await;
     }
 
     async fn recv<D: serde::de::DeserializeOwned>(&mut self) -> D {

tests/ws.rs

@@ -20,7 +20,7 @@ async fn serve_ws() -> ServerShutdown {
 
 struct WsClient {
     socket: WebSocketStream<MaybeTlsStream<tokio::net::TcpStream>>,
-    id: u64,
+    id: usize,
 }
 
 impl WsClient {
@@ -37,24 +37,17 @@ impl WsClient {
             _ => panic!("unexpected message type"),
         }
     }
+}
 
-    fn next_id(&mut self) -> u64 {
+impl TestClient for WsClient {
+    fn next_id(&mut self) -> usize {
         let id = self.id;
         self.id += 1;
         id
     }
-}
 
-impl TestClient for WsClient {
-    async fn send<S: serde::Serialize>(&mut self, method: &str, params: &S) {
-        let id = self.next_id();
-        self.send_inner(&serde_json::json!({
-            "jsonrpc": "2.0",
-            "id": id,
-            "method": method,
-            "params": params,
-        }))
-        .await;
+    async fn send_raw<S: serde::Serialize>(&mut self, msg: &S) {
+        self.send_inner(msg).await;
     }
 
     async fn recv<D: serde::de::DeserializeOwned>(&mut self) -> D {