feat: add rpc namespace (#994)

* Implement Rpc namespace

* Review comment

* Dependency fix

---------

Co-authored-by: Mikhail Sozin <[email protected]>

crates/provider/Cargo.toml

@@ -32,6 +32,7 @@ alloy-rpc-types-eth.workspace = true
 alloy-rpc-types-trace = { workspace = true, optional = true }
 alloy-rpc-types-txpool = { workspace = true, optional = true }
 alloy-rpc-types-engine = { workspace = true, optional = true }
+alloy-rpc-types = { workspace = true, optional = true }
 alloy-transport-http = { workspace = true, optional = true }
 alloy-transport-ipc = { workspace = true, optional = true }
 alloy-transport-ws = { workspace = true, optional = true }
@@ -98,4 +99,5 @@ debug-api = ["dep:alloy-rpc-types-trace"]
 engine-api = ["dep:alloy-rpc-types-engine"]
 net-api = []
 trace-api = ["dep:alloy-rpc-types-trace"]
+rpc-api = ["dep:alloy-rpc-types"]
 txpool-api = ["dep:alloy-rpc-types-txpool"]

crates/provider/src/ext/mod.rs

@@ -30,6 +30,11 @@ mod trace;
 #[cfg(feature = "trace-api")]
 pub use trace::{TraceApi, TraceCallList};
 
+#[cfg(feature = "rpc-api")]
+mod rpc;
+#[cfg(feature = "rpc-api")]
+pub use rpc::RpcApi;
+
 #[cfg(feature = "txpool-api")]
 mod txpool;
 #[cfg(feature = "txpool-api")]

crates/provider/src/ext/rpc.rs

@@ -0,0 +1,27 @@
+//! This module extends the Ethereum JSON-RPC provider with the Rpc namespace's RPC methods.
+use crate::Provider;
+use alloy_network::Network;
+use alloy_rpc_types::RpcModules;
+use alloy_transport::{Transport, TransportResult};
+
+/// The rpc API provides methods to get information about the RPC server itself, such as the enabled
+/// namespaces.
+#[cfg_attr(target_arch = "wasm32", async_trait::async_trait(?Send))]
+#[cfg_attr(not(target_arch = "wasm32"), async_trait::async_trait)]
+pub trait RpcApi<N, T>: Send + Sync {
+    /// Lists the enabled RPC namespaces and the versions of each.
+    async fn rpc_modules(&self) -> TransportResult<RpcModules>;
+}
+
+#[cfg_attr(target_arch = "wasm32", async_trait::async_trait(?Send))]
+#[cfg_attr(not(target_arch = "wasm32"), async_trait::async_trait)]
+impl<N, T, P> RpcApi<N, T> for P
+where
+    N: Network,
+    T: Transport + Clone,
+    P: Provider<T, N>,
+{
+    async fn rpc_modules(&self) -> TransportResult<RpcModules> {
+        self.client().request("rpc_modules", ()).await
+    }
+}

crates/rpc-types/Cargo.toml

@@ -28,6 +28,10 @@ alloy-rpc-types-eth = { workspace = true, optional = true }
 alloy-rpc-types-mev = { workspace = true, optional = true }
 alloy-rpc-types-trace = { workspace = true, optional = true }
 alloy-rpc-types-txpool = { workspace = true, optional = true }
+serde = { workspace = true, features = ["derive", "std"]}
+
+[dev-dependencies]
+serde_json.workspace = true
 
 [features]
 default = ["eth"]

crates/rpc-types/src/lib.rs

@@ -8,6 +8,9 @@
 
 pub use alloy_serde as serde_helpers;
 
+mod rpc;
+pub use rpc::*;
+
 #[cfg(feature = "admin")]
 pub use alloy_rpc_types_admin as admin;
 

crates/rpc-types/src/rpc.rs

@@ -0,0 +1,42 @@
+//! Types for the `rpc` API.
+use serde::{Deserialize, Serialize};
+use std::collections::HashMap;
+
+/// Represents the `rpc_modules` response, which returns the
+/// list of all available modules on that transport and their version
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, Default)]
+#[serde(transparent)]
+pub struct RpcModules {
+    module_map: HashMap<String, String>,
+}
+
+impl RpcModules {
+    /// Create a new instance of `RPCModules`
+    pub const fn new(module_map: HashMap<String, String>) -> Self {
+        Self { module_map }
+    }
+
+    /// Consumes self and returns the inner hashmap mapping module names to their versions
+    pub fn into_modules(self) -> HashMap<String, String> {
+        self.module_map
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    #[test]
+    fn test_parse_module_versions_roundtrip() {
+        let s = r#"{"txpool":"1.0","trace":"1.0","eth":"1.0","web3":"1.0","net":"1.0"}"#;
+        let module_map = HashMap::from([
+            ("txpool".to_owned(), "1.0".to_owned()),
+            ("trace".to_owned(), "1.0".to_owned()),
+            ("eth".to_owned(), "1.0".to_owned()),
+            ("web3".to_owned(), "1.0".to_owned()),
+            ("net".to_owned(), "1.0".to_owned()),
+        ]);
+        let m = RpcModules::new(module_map);
+        let de_serialized: RpcModules = serde_json::from_str(s).unwrap();
+        assert_eq!(de_serialized, m);
+    }
+}