Peter/river exceptions not excepting (#161)

Why
===

We validate the errors which might have some schema like extra fields,
then we toss them away like unwanted trash. This is bad.

What changed
============

The RiverServiceException class is updated to accept and store the
original deserialized RiverError object.
Client sessions now pass this underlying_error when raising service
exceptions, making the full error payload accessible.

Test plan
=========

Ran ai-infra with this. The CI/CD for that will catch anything and it's
also like low key just adding stuff.

Author: peter-zhong-replit

src/replit_river/client_session.py

@@ -252,7 +252,11 @@ async def send_rpc(
                 except Exception as e:
                     raise RiverException("error_deserializer", str(e)) from e
                 raise exception_from_message(error.code)(
-                    error.code, error.message, service_name, procedure_name
+                    error.code,
+                    error.message,
+                    service_name,
+                    procedure_name,
+                    underlying_error=error,
                 )
             return response_deserializer(response["payload"])
         except RiverException as e:
@@ -338,7 +342,11 @@ async def send_upload(
                 except Exception as e:
                     raise RiverException("error_deserializer", str(e)) from e
                 raise exception_from_message(error.code)(
-                    error.code, error.message, service_name, procedure_name
+                    error.code,
+                    error.message,
+                    service_name,
+                    procedure_name,
+                    underlying_error=error,
                 )
 
             return response_deserializer(response["payload"])

src/replit_river/error_schema.py

@@ -51,12 +51,18 @@ class RiverServiceException(RiverException):
     """Exception raised by river as a result of a fault in the service running river."""
 
     def __init__(
-        self, code: str, message: str, service: str | None, procedure: str | None
+        self,
+        code: str,
+        message: str,
+        service: str | None,
+        procedure: str | None,
+        underlying_error: RiverError | None = None,
     ) -> None:
         self.code = code
         self.message = message
         self.service = service
         self.procedure = procedure
+        self.underlying_error = underlying_error
         service = service or "N/A"
         procedure = procedure or "N/A"
         msg = (

src/replit_river/v2/session.py

@@ -790,7 +790,11 @@ async def send_rpc[R, A](
                 except Exception as e:
                     raise RiverException("error_deserializer", str(e)) from e
                 raise exception_from_message(error.code)(
-                    error.code, error.message, service_name, procedure_name
+                    error.code,
+                    error.message,
+                    service_name,
+                    procedure_name,
+                    underlying_error=error,
                 )
 
             return response_deserializer(result["payload"])
@@ -899,7 +903,11 @@ async def send_upload[I, R, A](
                 except Exception as e:
                     raise RiverException("error_deserializer", str(e)) from e
                 raise exception_from_message(error.code)(
-                    error.code, error.message, service_name, procedure_name
+                    error.code,
+                    error.message,
+                    service_name,
+                    procedure_name,
+                    underlying_error=error,
                 )
 
             return response_deserializer(result["payload"])