Add uninstrument test for sqlalchemy (#1471)

CHANGELOG.md

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+- Add uninstrument test for sqlalchemy
+  ([#1471](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/1471))
 - `opentelemetry-instrumentation-tortoiseorm` Initial release
   ([#685](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/685))
 - Add metric instrumentation for tornado

instrumentation/opentelemetry-instrumentation-sqlalchemy/tests/test_sqlalchemy.py

@@ -227,3 +227,29 @@ async def run():
             )
 
         asyncio.get_event_loop().run_until_complete(run())
+
+    def test_uninstrument(self):
+        engine = create_engine("sqlite:///:memory:")
+        SQLAlchemyInstrumentor().instrument(
+            engine=engine,
+            tracer_provider=self.tracer_provider,
+        )
+        cnx = engine.connect()
+        cnx.execute("SELECT	1 + 1;").fetchall()
+        spans = self.memory_exporter.get_finished_spans()
+
+        self.assertEqual(len(spans), 2)
+        # first span - the connection to the db
+        self.assertEqual(spans[0].name, "connect")
+        self.assertEqual(spans[0].kind, trace.SpanKind.CLIENT)
+        # second span - the query itself
+        self.assertEqual(spans[1].name, "SELECT :memory:")
+        self.assertEqual(spans[1].kind, trace.SpanKind.CLIENT)
+
+        self.memory_exporter.clear()
+        SQLAlchemyInstrumentor().uninstrument()
+        engine2 = create_engine("sqlite:///:memory:")
+        cnx2 = engine2.connect()
+        cnx2.execute("SELECT	2 + 2;").fetchall()
+        spans = self.memory_exporter.get_finished_spans()
+        self.assertEqual(len(spans), 0)