proc macro: support camelCase & snake_case for object params (#921)

* proc macro: support camelCase & snake_case for object params

* switch to heck for converting case

* fix ui test

proc-macros/Cargo.toml

@@ -17,6 +17,7 @@ proc-macro2 = "1.0"
 quote = "1.0"
 syn = { version = "1.0", default-features = false, features = ["extra-traits", "full", "visit", "parsing"] }
 proc-macro-crate = "1"
+heck = "0.4.0"
 
 [dev-dependencies]
 jsonrpsee = { path = "../jsonrpsee", features = ["full"] }

proc-macros/src/render_server.rs

@@ -25,14 +25,15 @@
 // DEALINGS IN THE SOFTWARE.
 
 use std::collections::HashSet;
+use std::str::FromStr;
 
 use super::RpcDescription;
 use crate::attributes::Resource;
 use crate::helpers::{generate_where_clause, is_option};
 use proc_macro2::{Span, TokenStream as TokenStream2};
 use quote::{quote, quote_spanned};
 use syn::punctuated::Punctuated;
-use syn::{parse_quote, ReturnType, Token};
+use syn::{parse_quote, token, AttrStyle, Attribute, Path, PathSegment, ReturnType, Token};
 
 impl RpcDescription {
 	pub(super) fn render_server(&self) -> Result<TokenStream2, syn::Error> {
@@ -387,8 +388,36 @@ impl RpcDescription {
 
 			let serde = self.jrps_server_item(quote! { core::__reexports::serde });
 			let serde_crate = serde.to_string();
+
 			let fields = params.iter().zip(generics.clone()).map(|((name, _), ty)| {
-				quote! { #name: #ty, }
+				let mut alias_vals = String::new();
+				alias_vals.push_str(&format!(
+					r#"alias = "{}""#,
+					heck::ToSnakeCase::to_snake_case(name.ident.to_string().as_str())
+				));
+				alias_vals.push(',');
+				alias_vals.push_str(&format!(
+					r#"alias = "{}""#,
+					heck::ToLowerCamelCase::to_lower_camel_case(name.ident.to_string().as_str())
+				));
+
+				let mut punc_attr = Punctuated::new();
+
+				punc_attr
+					.push_value(PathSegment { ident: quote::format_ident!("serde"), arguments: Default::default() });
+
+				let serde_alias = Attribute {
+					pound_token: token::Pound::default(),
+					style: AttrStyle::Outer,
+					bracket_token: Default::default(),
+					path: Path { leading_colon: None, segments: punc_attr },
+					tokens: TokenStream2::from_str(&format!("({})", alias_vals.as_str())).unwrap(),
+				};
+
+				quote! {
+					#serde_alias
+					#name: #ty,
+				}
 			});
 			let destruct = params.iter().map(|(name, _)| quote! { parsed.#name });
 			let types = params.iter().map(|(_, ty)| ty);

proc-macros/tests/ui/incorrect/rpc/rpc_empty_bounds.stderr

@@ -1,23 +1,23 @@
 error[E0277]: the trait bound `<Conf as Config>::Hash: Serialize` is not satisfied
-   --> tests/ui/incorrect/rpc/rpc_empty_bounds.rs:10:1
-    |
-10  | #[rpc(server, client, namespace = "foo", client_bounds(), server_bounds())]
-    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Serialize` is not implemented for `<Conf as Config>::Hash`
-    |
+  --> tests/ui/incorrect/rpc/rpc_empty_bounds.rs:10:1
+   |
+10 | #[rpc(server, client, namespace = "foo", client_bounds(), server_bounds())]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Serialize` is not implemented for `<Conf as Config>::Hash`
+   |
 note: required by a bound in `RpcModule::<Context>::register_method`
-   --> $WORKSPACE/core/src/server/rpc_module.rs
-    |
-    |         R: Serialize,
-    |            ^^^^^^^^^ required by this bound in `RpcModule::<Context>::register_method`
-    = note: this error originates in the attribute macro `rpc` (in Nightly builds, run with -Z macro-backtrace for more info)
+  --> $WORKSPACE/core/src/server/rpc_module.rs
+   |
+   |         R: Serialize,
+   |            ^^^^^^^^^ required by this bound in `RpcModule::<Context>::register_method`
+   = note: this error originates in the attribute macro `rpc` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0277]: the trait bound `for<'de> <Conf as Config>::Hash: Deserialize<'de>` is not satisfied
   --> tests/ui/incorrect/rpc/rpc_empty_bounds.rs:10:1
    |
 10 | #[rpc(server, client, namespace = "foo", client_bounds(), server_bounds())]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `for<'de> Deserialize<'de>` is not implemented for `<Conf as Config>::Hash`
    |
-   = note: required because of the requirements on the impl of `DeserializeOwned` for `<Conf as Config>::Hash`
+   = note: required for `<Conf as Config>::Hash` to implement `DeserializeOwned`
 note: required by a bound in `request`
   --> $WORKSPACE/core/src/client/mod.rs
    |

tests/tests/proc_macros.rs

@@ -375,3 +375,26 @@ async fn calls_with_bad_params() {
 		matches!(err, Error::Call(CallError::Custom (err)) if err.message().contains("invalid type: integer `2`, expected a string") && err.code() == ErrorCode::InvalidParams.code())
 	);
 }
+
+#[tokio::test]
+async fn calls_with_object_params_works() {
+	let server = ServerBuilder::default().build("127.0.0.1:0").await.unwrap();
+	let addr = server.local_addr().unwrap();
+	let server_url = format!("ws://{}", addr);
+	let _handle = server.start(RpcServerImpl.into_rpc()).unwrap();
+	let client = WsClientBuilder::default().build(&server_url).await.unwrap();
+
+	// snake_case params
+	let mut params = ObjectParams::new();
+	params.insert("param_a", 0).unwrap();
+	params.insert("param_b", "0x0").unwrap();
+
+	assert_eq!(client.request::<u64, ObjectParams>("foo_foo", params).await.unwrap(), 42);
+
+	// camelCase params.
+	let mut params = ObjectParams::new();
+	params.insert("paramA", 0).unwrap();
+	params.insert("paramB", "0x0").unwrap();
+
+	assert_eq!(client.request::<u64, ObjectParams>("foo_foo", params).await.unwrap(), 42);
+}