Add support for state_call JSON-RPC function

bin/light-base/src/json_rpc_service.rs

@@ -798,6 +798,20 @@ impl<TPlat: Platform> Background<TPlat> {
                 self.rpc_methods(request_id, &state_machine_request_id)
                     .await;
             }
+            methods::MethodCall::state_call {
+                name,
+                parameters,
+                hash,
+            } => {
+                self.state_call(
+                    request_id,
+                    &state_machine_request_id,
+                    &name,
+                    parameters,
+                    hash,
+                )
+                .await;
+            }
             methods::MethodCall::state_getKeysPaged {
                 prefix,
                 count,
@@ -1069,7 +1083,6 @@ impl<TPlat: Platform> Background<TPlat> {
             | methods::MethodCall::grandpa_roundState { .. }
             | methods::MethodCall::offchain_localStorageGet { .. }
             | methods::MethodCall::offchain_localStorageSet { .. }
-            | methods::MethodCall::state_call { .. }
             | methods::MethodCall::state_getKeys { .. }
             | methods::MethodCall::state_getPairs { .. }
             | methods::MethodCall::state_getReadProof { .. }

bin/light-base/src/json_rpc_service/state_chain.rs

@@ -835,6 +835,49 @@ impl<TPlat: Platform> Background<TPlat> {
             .await;
     }
 
+    /// Handles a call to [`methods::MethodCall::state_call`].
+    pub(super) async fn state_call(
+        self: &Arc<Self>,
+        request_id: &str,
+        state_machine_request_id: &requests_subscriptions::RequestId,
+        function_to_call: &str,
+        call_parameters: methods::HexString,
+        hash: Option<methods::HashHexString>,
+    ) {
+        let block_hash = if let Some(hash) = hash {
+            hash.0
+        } else {
+            header::hash_from_scale_encoded_header(
+                &sub_utils::subscribe_best(&self.runtime_service).await.0,
+            )
+        };
+
+        let result = self
+            .runtime_call(
+                &block_hash,
+                function_to_call,
+                iter::once(call_parameters.0),
+                3,
+                Duration::from_secs(10),
+                NonZeroU32::new(3).unwrap(),
+            )
+            .await;
+
+        let response = match result {
+            Ok(data) => methods::Response::state_call(methods::HexString(data.to_vec()))
+                .to_json_response(request_id),
+            Err(error) => json_rpc::parse::build_error_response(
+                request_id,
+                json_rpc::parse::ErrorResponse::ServerError(-32000, &error.to_string()),
+                None,
+            ),
+        };
+
+        self.requests_subscriptions
+            .respond(state_machine_request_id, response)
+            .await;
+    }
+
     /// Handles a call to [`methods::MethodCall::state_getKeysPaged`].
     pub(super) async fn state_get_keys_paged(
         self: &Arc<Self>,

bin/wasm-node/CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### Added
 
+- Add support for the `state_call` JSON-RPC function. ([#2374](https://github.com/paritytech/smoldot/pull/2374))
 - The `relay_chain` and `para_id` fields in chain specifications can now alternatively be named respectively `relayChain` and `paraId`. This increases consistency with the other fields of chain specifications, which are all camelCase. ([#2366](https://github.com/paritytech/smoldot/pull/2366))
 
 ### Fixed

src/json_rpc/methods.rs

@@ -365,7 +365,7 @@ define_methods! {
     payment_queryInfo(extrinsic: HexString, hash: Option<HashHexString>) -> RuntimeDispatchInfo,
     /// Returns a list of all JSON-RPC methods that are available.
     rpc_methods() -> RpcMethods,
-    state_call() -> () [state_callAt], // TODO:
+    state_call(name: Cow<'a, str>, parameters: HexString, hash: Option<HashHexString>) -> HexString [state_callAt],
     state_getKeys() -> (), // TODO:
     state_getKeysPaged(prefix: Option<HexString>, count: u32, start_key: Option<HexString>, hash: Option<HashHexString>) -> Vec<HexString> [state_getKeysPagedAt],
     state_getMetadata(hash: Option<HashHexString>) -> HexString,