refactor: decouple ReflectionClient to possibly publish in a separate crate

granc/src/core.rs

@@ -72,10 +72,9 @@ pub async fn run(input: Input) -> Result<Output, CoreError> {
         Some(path) => DescriptorRegistry::from_file(path)?,
         // If no proto-set file is passed, we'll try to reach the server reflection service
         None => {
-            let mut service = ReflectionClient::connect(input.url.clone()).await?;
-            service
-                .resolve_service_descriptor_registry(&input.service)
-                .await?
+            let mut client = ReflectionClient::connect(input.url.clone()).await?;
+            let fd_set = client.file_descriptor_set_by_symbol(&input.service).await?;
+            DescriptorRegistry::from_file_descriptor_set(fd_set)?
         }
     };
 

granc/src/core/reflection/client.rs

@@ -19,7 +19,6 @@ use super::generated::reflection_v1::{
     server_reflection_response::MessageResponse,
 };
 use crate::core::BoxError;
-use crate::core::reflection::DescriptorRegistry;
 use http_body::Body as HttpBody;
 use prost::Message;
 use prost_types::{FileDescriptorProto, FileDescriptorSet};
@@ -64,9 +63,6 @@ pub enum ReflectionResolveError {
 
     #[error("Failed to decode FileDescriptorProto: {0}")]
     DecodeError(#[from] prost::DecodeError),
-
-    #[error("Failed to build DescriptorRegistry: {0}")]
-    RegistryError(#[from] crate::core::reflection::registry::DescriptorError),
 }
 
 /// A generic client for the gRPC Server Reflection Protocol.
@@ -99,10 +95,21 @@ where
     T::ResponseBody: HttpBody<Data = tonic::codegen::Bytes> + Send + 'static,
     <T::ResponseBody as HttpBody>::Error: Into<BoxError> + Send,
 {
-    pub async fn resolve_service_descriptor_registry(
+    /// Asks the reflection service for the file containing the requested symbol (e.g., `my.package.MyService`).
+    ///
+    /// **Recursive Resolution**:
+    ///    - The server returns a `FileDescriptorProto`.
+    ///    - The client inspects the imports (dependencies) of that file.
+    ///    - It recursively requests any missing dependencies until the full `FileDescriptorSet` is built.
+    ///
+    /// # Returns
+    ///
+    /// * `Ok(fd_set)` - Successful reflection requests execution.
+    /// * `Err(ReflectionResolveError)` - Failed to request file descriptors to the reflection service.
+    pub async fn file_descriptor_set_by_symbol(
         &mut self,
         service_name: &str,
-    ) -> Result<DescriptorRegistry, ReflectionResolveError> {
+    ) -> Result<FileDescriptorSet, ReflectionResolveError> {
         // Initialize Stream
         let (tx, rx) = mpsc::channel(100);
 
@@ -133,7 +140,7 @@ where
             file: file_map.into_values().collect(),
         };
 
-        Ok(DescriptorRegistry::from_file_descriptor_set(fd_set)?)
+        Ok(fd_set)
     }
 
     async fn collect_descriptors(

granc/src/core/reflection/client/integration_test.rs

@@ -1,4 +1,5 @@
 use crate::core::reflection::{
+    DescriptorRegistry,
     client::{
         ReflectionClient, ReflectionResolveError, integration_test::dummy_service::DummyEchoService,
     },
@@ -28,10 +29,13 @@ fn setup_reflection_client()
 async fn test_reflection_client_fetches_unary_echo() {
     let mut client = setup_reflection_client();
 
-    let registry = client
-        .resolve_service_descriptor_registry("echo.EchoService")
+    let fd_set = client
+        .file_descriptor_set_by_symbol("echo.EchoService")
         .await
-        .expect("Failed to resolve service descriptor registry");
+        .expect("Failed to fetch file descriptor set by symbol");
+
+    let registry = DescriptorRegistry::from_file_descriptor_set(fd_set)
+        .expect("Failed to build descriptor registry");
 
     let method = registry
         .get_method_descriptor("echo.EchoService", "UnaryEcho")
@@ -56,10 +60,13 @@ async fn test_reflection_client_fetches_unary_echo() {
 async fn test_reflection_client_fetches_server_streaming_echo() {
     let mut client = setup_reflection_client();
 
-    let registry = client
-        .resolve_service_descriptor_registry("echo.EchoService")
+    let fd_set = client
+        .file_descriptor_set_by_symbol("echo.EchoService")
         .await
-        .expect("Failed to resolve service descriptor registry");
+        .expect("Failed to fetch file descriptor set by symbol");
+
+    let registry = DescriptorRegistry::from_file_descriptor_set(fd_set)
+        .expect("Failed to build descriptor registry");
 
     let method = registry
         .get_method_descriptor("echo.EchoService", "ServerStreamingEcho")
@@ -84,10 +91,13 @@ async fn test_reflection_client_fetches_server_streaming_echo() {
 async fn test_reflection_client_fetches_client_streaming_echo() {
     let mut client = setup_reflection_client();
 
-    let registry = client
-        .resolve_service_descriptor_registry("echo.EchoService")
+    let fd_set = client
+        .file_descriptor_set_by_symbol("echo.EchoService")
         .await
-        .expect("Failed to resolve service descriptor registry");
+        .expect("Failed to fetch file descriptor set by symbol");
+
+    let registry = DescriptorRegistry::from_file_descriptor_set(fd_set)
+        .expect("Failed to build descriptor registry");
 
     let method = registry
         .get_method_descriptor("echo.EchoService", "ClientStreamingEcho")
@@ -112,10 +122,13 @@ async fn test_reflection_client_fetches_client_streaming_echo() {
 async fn test_reflection_client_fetches_bidirectional_echo() {
     let mut client = setup_reflection_client();
 
-    let registry = client
-        .resolve_service_descriptor_registry("echo.EchoService")
+    let fd_set = client
+        .file_descriptor_set_by_symbol("echo.EchoService")
         .await
-        .expect("Failed to resolve service descriptor registry");
+        .expect("Failed to fetch file descriptor set by symbol");
+
+    let registry = DescriptorRegistry::from_file_descriptor_set(fd_set)
+        .expect("Failed to build descriptor registry");
 
     let method = registry
         .get_method_descriptor("echo.EchoService", "BidirectionalEcho")
@@ -139,7 +152,7 @@ async fn test_reflection_service_not_found_error() {
     let mut client = setup_reflection_client();
 
     let result: Result<_, _> = client
-        .resolve_service_descriptor_registry("non.existent.Service")
+        .file_descriptor_set_by_symbol("non.existent.Service")
         .await;
 
     assert!(matches!(
@@ -161,7 +174,7 @@ async fn test_server_does_not_support_reflection() {
 
     // The client will attempt to call `/grpc.reflection.v1.ServerReflection/ServerReflectionInfo` on this service.
     let result = client
-        .resolve_service_descriptor_registry("echo.EchoService")
+        .file_descriptor_set_by_symbol("echo.EchoService")
         .await;
 
     match result {