feat: add namespace_separator option for RPC methods (#1544)

* feat: add namespace_separator option for RPC methods

* test: add tests for namespace_separator formatting with dot and slash

Author: YakupAltay

proc-macros/src/lib.rs

@@ -80,7 +80,7 @@ pub(crate) mod visitor;
 /// that generated for it by the macro.
 ///
 /// ```ignore
-/// #[rpc(client, server, namespace = "foo")]
+/// #[rpc(client, server, namespace = "foo", namespace_separator = ".")]
 /// pub trait Rpc {
 ///     #[method(name = "foo")]
 ///     async fn async_method(&self, param_a: u8, param_b: String) -> u16;
@@ -147,6 +147,8 @@ pub(crate) mod visitor;
 ///   implementation's methods conveniently.
 /// - `namespace`: add a prefix to all the methods and subscriptions in this RPC. For example, with namespace `foo` and
 ///   method `spam`, the resulting method name will be `foo_spam`.
+/// - `namespace_separator`: customize the separator used between namespace and method name. Defaults to `_`.
+///		For example, `namespace = "foo", namespace_separator = "."` results in method names like `foo.bar` instead of `foo_bar`.
 /// - `server_bounds`: replace *all* auto-generated trait bounds with the user-defined ones for the server
 ///   implementation.
 /// - `client_bounds`: replace *all* auto-generated trait bounds with the user-defined ones for the client

proc-macros/src/rpc_macro.rs

@@ -262,6 +262,8 @@ pub struct RpcDescription {
 	pub(crate) needs_client: bool,
 	/// Optional prefix for RPC namespace.
 	pub(crate) namespace: Option<String>,
+	/// Optional separator between namespace and method name. Defaults to `_`.
+	pub(crate) namespace_separator: Option<String>,
 	/// Trait definition in which all the attributes were stripped.
 	pub(crate) trait_def: syn::ItemTrait,
 	/// List of RPC methods defined in the trait.
@@ -276,12 +278,20 @@ pub struct RpcDescription {
 
 impl RpcDescription {
 	pub fn from_item(attr: Attribute, mut item: syn::ItemTrait) -> syn::Result<Self> {
-		let [client, server, namespace, client_bounds, server_bounds] =
-			AttributeMeta::parse(attr)?.retain(["client", "server", "namespace", "client_bounds", "server_bounds"])?;
+		let [client, server, namespace, namespace_separator, client_bounds, server_bounds] =
+			AttributeMeta::parse(attr)?.retain([
+				"client",
+				"server",
+				"namespace",
+				"namespace_separator",
+				"client_bounds",
+				"server_bounds",
+			])?;
 
 		let needs_server = optional(server, Argument::flag)?.is_some();
 		let needs_client = optional(client, Argument::flag)?.is_some();
 		let namespace = optional(namespace, Argument::string)?;
+		let namespace_separator = optional(namespace_separator, Argument::string)?;
 		let client_bounds = optional(client_bounds, Argument::group)?;
 		let server_bounds = optional(server_bounds, Argument::group)?;
 		if !needs_server && !needs_client {
@@ -368,6 +378,7 @@ impl RpcDescription {
 			needs_server,
 			needs_client,
 			namespace,
+			namespace_separator,
 			trait_def: item,
 			methods,
 			subscriptions,
@@ -400,12 +411,18 @@ impl RpcDescription {
 		quote! { #jsonrpsee::#item }
 	}
 
-	/// Based on the namespace, renders the full name of the RPC method/subscription.
+	/// Based on the namespace and separator, renders the full name of the RPC method/subscription.
 	/// Examples:
-	/// For namespace `foo` and method `makeSpam`, result will be `foo_makeSpam`.
-	/// For no namespace and method `makeSpam` it will be just `makeSpam`.
+	/// For namespace `foo`, method `makeSpam`, and separator `_`, result will be `foo_makeSpam`.
+	/// For separator `.`, result will be `foo.makeSpam`.
+	/// For no namespace, returns just `makeSpam`.
 	pub(crate) fn rpc_identifier<'a>(&self, method: &'a str) -> Cow<'a, str> {
-		if let Some(ns) = &self.namespace { format!("{ns}_{method}").into() } else { Cow::Borrowed(method) }
+		if let Some(ns) = &self.namespace {
+			let sep = self.namespace_separator.as_deref().unwrap_or("_");
+			format!("{ns}{sep}{method}").into()
+		} else {
+			Cow::Borrowed(method)
+		}
 	}
 }
 

tests/tests/proc_macros.rs

@@ -296,6 +296,60 @@ async fn macro_zero_copy_cow() {
 	assert_eq!(resp, r#"{"jsonrpc":"2.0","id":0,"result":"Zero copy params: false"}"#);
 }
 
+#[tokio::test]
+async fn namespace_separator_dot_formatting_works() {
+	use jsonrpsee::core::async_trait;
+	use jsonrpsee::proc_macros::rpc;
+	use serde_json::json;
+
+	#[rpc(server, namespace = "foo", namespace_separator = ".")]
+	pub trait DotSeparatorRpc {
+		#[method(name = "dot")]
+		fn dot(&self, a: u32, b: &str) -> Result<String, jsonrpsee::types::ErrorObjectOwned>;
+	}
+
+	struct DotImpl;
+
+	#[async_trait]
+	impl DotSeparatorRpcServer for DotImpl {
+		fn dot(&self, a: u32, b: &str) -> Result<String, jsonrpsee::types::ErrorObjectOwned> {
+			Ok(format!("Called with: {}, {}", a, b))
+		}
+	}
+
+	let module = DotImpl.into_rpc();
+	let res: String = module.call("foo.dot", [json!(1_u64), json!("test")]).await.unwrap();
+
+	assert_eq!(&res, "Called with: 1, test");
+}
+
+#[tokio::test]
+async fn namespace_separator_slash_formatting_works() {
+	use jsonrpsee::core::async_trait;
+	use jsonrpsee::proc_macros::rpc;
+	use serde_json::json;
+
+	#[rpc(server, namespace = "math", namespace_separator = "/")]
+	pub trait SlashSeparatorRpc {
+		#[method(name = "add")]
+		fn add(&self, x: i32, y: i32) -> Result<i32, jsonrpsee::types::ErrorObjectOwned>;
+	}
+
+	struct SlashImpl;
+
+	#[async_trait]
+	impl SlashSeparatorRpcServer for SlashImpl {
+		fn add(&self, x: i32, y: i32) -> Result<i32, jsonrpsee::types::ErrorObjectOwned> {
+			Ok(x + y)
+		}
+	}
+
+	let module = SlashImpl.into_rpc();
+	let result: i32 = module.call("math/add", [json!(20), json!(22)]).await.unwrap();
+
+	assert_eq!(result, 42);
+}
+
 // Disabled on MacOS as GH CI timings on Mac vary wildly (~100ms) making this test fail.
 #[cfg(not(target_os = "macos"))]
 #[ignore]