test(pydantic-ai): Create event loop before invoking sync methods (#6475)

Pydantic AI creates an event loop when synchronous agent methods run without an active loop, but does not close it. Manually create and manage an event loop in tests that do not rely on `pytest-asyncio`.

Author: alexander-alderman-webb

tests/integrations/pydantic_ai/test_pydantic_ai.py

@@ -55,6 +55,20 @@ def inner():
     return inner
 
 
+@pytest.fixture
+def sync_event_loop():
+    # Pydantic AI creates an event loop if there is none and doesn't close it in synchronous methods.
+    # Run with "-X tracemalloc=25 -W default::ResourceWarning" to reproduce.
+    # https://github.com/pydantic/pydantic-ai/commit/a58dd47f9cd6494665e47bf7cf71fccbfce2c0dd
+    loop = asyncio.new_event_loop()
+    asyncio.set_event_loop(loop)
+    try:
+        yield loop
+    finally:
+        loop.close()
+        asyncio.set_event_loop(None)
+
+
 @pytest.mark.parametrize("span_streaming", [True, False])
 @pytest.mark.parametrize("stream_gen_ai_spans", [True, False])
 @pytest.mark.asyncio
@@ -284,6 +298,7 @@ def test_agent_run_sync(
     get_test_agent,
     stream_gen_ai_spans,
     span_streaming,
+    sync_event_loop,
 ):
     """
     Test that the integration creates spans for sync agent runs.
@@ -381,6 +396,7 @@ def test_agent_run_sync_model_error(
     capture_items,
     stream_gen_ai_spans,
     span_streaming,
+    sync_event_loop,
 ):
     sentry_init(
         integrations=[PydanticAIIntegration()],
@@ -1985,7 +2001,7 @@ async def test_context_cleanup_after_run(sentry_init, get_test_agent):
     assert "pydantic_ai_agent" not in scope._contexts
 
 
-def test_context_cleanup_after_run_sync(sentry_init, get_test_agent):
+def test_context_cleanup_after_run_sync(sentry_init, get_test_agent, sync_event_loop):
     """
     Test that the pydantic_ai_agent context is properly cleaned up after sync agent execution.
     """