Handle empty statement in psycopg instrumentation (#2644)

CHANGELOG.md

@@ -40,6 +40,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([#2590](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/2590))
 - Reference symbols from generated semantic conventions
   ([#2611](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/2611))
+- `opentelemetry-instrumentation-psycopg` Bugfix: Handle empty statement.
+  ([#2644](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/2644))
 - `opentelemetry-instrumentation-confluent-kafka` Confluent Kafka: Ensure consume span is ended when consumer is closed
   ([#2640](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/2640))
 

instrumentation/opentelemetry-instrumentation-psycopg/src/opentelemetry/instrumentation/psycopg/__init__.py

@@ -269,7 +269,8 @@ class CursorTracer(dbapi.CursorTracer):
         if isinstance(statement, Composed):
             statement = statement.as_string(cursor)
 
-        if isinstance(statement, str):
+        # `statement` can be empty string. See #2643
+        if statement and isinstance(statement, str):
             # Strip leading comments so we get the operation name.
             return self._leading_comment_remover.sub("", statement).split()[0]
 

instrumentation/opentelemetry-instrumentation-psycopg/tests/test_psycopg_integration.py

@@ -245,14 +245,18 @@ class TestPostgresqlIntegration(PostgresqlIntegrationTestMixin, TestBase):
         cursor.execute("/* leading comment */ query")
         cursor.execute("/* leading comment */ query /* trailing comment */")
         cursor.execute("query /* trailing comment */")
+        cursor.execute("")
+        cursor.execute("--")
         spans_list = self.memory_exporter.get_finished_spans()
-        self.assertEqual(len(spans_list), 6)
+        self.assertEqual(len(spans_list), 8)
         self.assertEqual(spans_list[0].name, "Test")
         self.assertEqual(spans_list[1].name, "multi")
         self.assertEqual(spans_list[2].name, "tab")
         self.assertEqual(spans_list[3].name, "query")
         self.assertEqual(spans_list[4].name, "query")
         self.assertEqual(spans_list[5].name, "query")
+        self.assertEqual(spans_list[6].name, "postgresql")
+        self.assertEqual(spans_list[7].name, "--")
 
     # pylint: disable=unused-argument
     def test_not_recording(self):