[asgi] add test for #1883

instrumentation/opentelemetry-instrumentation-asgi/tests/test_asgi_middleware.py

@@ -14,6 +14,7 @@
 
 # pylint: disable=too-many-lines
 
+import asyncio
 import sys
 import unittest
 from timeit import default_timer
@@ -796,5 +797,34 @@ async def wrapped_app(scope, receive, send):
  )
 
 
+class TestAsgiApplicationRaisingError(AsgiTestBase):
+
+ def tearDown(self):
+ pass
+
+ @mock.patch(
+ "opentelemetry.instrumentation.asgi.collect_custom_request_headers_attributes",
+ side_effect=ValueError("whatever"),
+ )
+ def test_asgi_issue_1883(self, mock_collect_custom_request_headers_attributes):
+ """
+ Test that exception UnboundLocalError local variable 'start' referenced before assignment is not raises
+ See https:/open-telemetry/opentelemetry-python-contrib/issues/1883
+ """
+ app = otel_asgi.OpenTelemetryMiddleware(simple_asgi)
+ self.seed_app(app)
+ self.send_default_request()
+ try:
+ asyncio.get_event_loop().run_until_complete(
+ self.communicator.stop()
+ )
+ except ValueError as exc_info:
+ self.assertEqual(exc_info.args[0], "whatever")
+ except Exception as exc_info:
+ self.fail("expecting ValueError('whatever'), received instead: " + str(exc_info))
+ else:
+ self.fail("expecting ValueError('whatever')")
+
+
 if __name__ == "__main__":
  unittest.main()