tests: use custom exceptiongroup handler

This way tests can still be run with older versions of trio and anyio

Author: VincentVanlaer

setup.py

@@ -82,7 +82,7 @@ def main():
                 "grpcio-tools",
                 "uvloop; platform_system!='Windows'",
                 "tblib>=1.3.2",
-                "trio>=0.24.0",
+                "trio>=0.11",
                 "pip-tools>=6.3.1",
                 "python-forge>=18.6",
                 "trustme",

tests/exceptiongroups.py

@@ -0,0 +1,31 @@
+from typing import Iterable
+from contextlib import contextmanager
+import sys
+
+if sys.version_info < (3, 11):
+    from exceptiongroup import ExceptionGroup
+
+
+def _unroll_exceptions(
+    exceptions: Iterable[Exception]
+) -> Iterable[Exception]:
+    res: list[Exception] = []
+    for exc in exceptions:
+        if isinstance(exc, ExceptionGroup):
+            res.extend(_unroll_exceptions(exc.exceptions))
+
+        else:
+            res.append(exc)
+    return res
+
+
+@contextmanager
+def unwrap_exceptiongroups_single():
+    try:
+        yield
+    except ExceptionGroup as e:
+        exceptions = _unroll_exceptions(e.exceptions)
+
+        assert len(exceptions) == 1, "Exception group contains multiple exceptions"
+
+        raise exceptions[0]

tests/test_echo.py

@@ -4,11 +4,11 @@
 import anyio
 import pytest
 import trustme
-import trio.testing
 
 import purerpc
 from purerpc.test_utils import run_purerpc_service_in_process, run_grpc_service_in_process, \
     async_iterable_to_list, random_payload, grpc_client_parallelize, purerpc_channel, purerpc_client_parallelize, grpc_channel
+from .exceptiongroups import unwrap_exceptiongroups_single
 
 pytestmark = pytest.mark.anyio
 
@@ -201,7 +201,7 @@ async def test_purerpc_client_disconnect(echo_pb2, echo_grpc):
         port = await tg.start(server.serve_async)
 
         # client
-        with trio.testing.RaisesGroup(anyio.ClosedResourceError, strict=False):
+        with pytest.raises(anyio.ClosedResourceError), unwrap_exceptiongroups_single():
             async with purerpc.insecure_channel("localhost", port) as channel:
                 stub = echo_grpc.EchoStub(channel)
 

tests/test_errors.py

@@ -6,6 +6,7 @@
 import purerpc
 from purerpc.test_utils import run_purerpc_service_in_process, run_grpc_service_in_process, grpc_channel, \
     grpc_client_parallelize, purerpc_channel
+from .exceptiongroups import unwrap_exceptiongroups_single
 
 pytestmark = pytest.mark.anyio
 
@@ -89,7 +90,7 @@ async def generator():
 
     stub = greeter_grpc.GreeterStub(channel)
 
-    with trio.testing.RaisesGroup(trio.testing.Matcher(ValueError, "oops"), strict=False):
+    with pytest.raises(ValueError, match="oops"), unwrap_exceptiongroups_single():
         async with stub.SayHelloToMany(generator()) as aiter:
             async for resp in aiter:
                 if resp.message == "2":