Don't swallow server-side exceptions

tests/functional/single_server/client_test.py

@@ -43,8 +43,11 @@ async def divide(semaphore, req):
 
 def test_server_error():
     client = ZeroClient(server.HOST, server.PORT)
-    msg = client.call("error", "some error")
-    assert msg is None
+    try:
+        msg = client.call("error", "some error")
+        raise AssertionError("Should have thrown an Exception")
+    except zero.error.RemoteException:
+        pass
 
 
 def test_default_timeout():

zero/client_server/client.py

@@ -4,11 +4,17 @@
 
 from zero import config
 from zero.encoder import Encoder, get_encoder
-from zero.error import MethodNotFoundException, TimeoutException
+from zero.error import MethodNotFoundException, TimeoutException, RemoteException
 from zero.utils.util import current_time_us, unique_id
 from zero.zero_mq import AsyncZeroMQClient, ZeroMQClient, get_async_client, get_client
 from zero.zero_mq.helpers import zpipe_async
 
+def check_response(resp_data):
+    if isinstance(resp_data, dict):
+        if e := resp_data.get("__zerror__method_not_found"):
+            raise MethodNotFoundException(e)
+        if e := resp_data.get("__zerror__server_exception"):
+            raise RemoteException(e)
 
 class ZeroClient:
     def __init__(
@@ -101,8 +107,7 @@ def _poll_data():
         while resp_id != req_id:
             resp_id, resp_data = _poll_data()
 
-        if isinstance(resp_data, dict) and "__zerror__method_not_found" in resp_data:
-            raise MethodNotFoundException(resp_data.get("__zerror__method_not_found"))
+        check_response(resp_data)
 
         return resp_data
 
@@ -237,7 +242,6 @@ async def _poll_data():
 
         resp_data = self._resp_map.pop(req_id)
 
-        if isinstance(resp_data, dict) and "__zerror__method_not_found" in resp_data:
-            raise MethodNotFoundException(resp_data.get("__zerror__method_not_found"))
+        check_response(resp_data)
 
         return resp_data

zero/client_server/worker.py

@@ -104,6 +104,7 @@ def handle_msg(self, rpc, msg):
 
         except Exception as exc:
             logging.exception(exc)
+            ret = {"__zerror__server_exception": repr(exc)}
 
         return ret
 

zero/error.py

@@ -12,3 +12,6 @@ class TimeoutException(ZeroException):
 
 class ConnectionException(ZeroException):
     pass
+
+class RemoteException(Exception):
+    pass