Adding a regression test for asynccursor bug

Adds a test to check that the async tracer is actually awaiting
cursor.execute.

On my machine, with the bug present, the duration is 14000ns. With the
bug patched the the duration is orders of magnitude larger.

Author: ibash

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

@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import asyncio
 import types
 from unittest import IsolatedAsyncioTestCase, mock
 
@@ -50,10 +51,13 @@ def __init__(self, *args, **kwargs):
         pass
 
     # pylint: disable=unused-argument, no-self-use
-    async def execute(self, query, params=None, throw_exception=False):
+    async def execute(self, query, params=None, throw_exception=False, delay=0.0):
         if throw_exception:
             raise psycopg.Error("Test Exception")
 
+        if delay:
+            await asyncio.sleep(delay)
+
     # pylint: disable=unused-argument, no-self-use
     async def executemany(self, query, params=None, throw_exception=False):
         if throw_exception:
@@ -492,3 +496,27 @@ async def test_not_recording_async(self):
             self.assertFalse(mock_span.set_status.called)
 
         PsycopgInstrumentor().uninstrument()
+
+    async def test_tracing_is_async(self):
+        PsycopgInstrumentor().instrument()
+
+        # before this async fix cursor.execute would take 14000 ns, delaying for
+        # 100,000ns
+        delay = 0.0001
+
+        async def test_async_connection():
+            acnx = await psycopg.AsyncConnection.connect("test")
+            async with acnx as cnx:
+                async with cnx.cursor() as cursor:
+                    await cursor.execute("SELECT * FROM test", delay=delay)
+
+        await test_async_connection()
+        spans_list = self.memory_exporter.get_finished_spans()
+        self.assertEqual(len(spans_list), 1)
+        span = spans_list[0]
+
+        # duration is nanoseconds
+        duration = span.end_time - span.start_time
+        self.assertGreater(duration, delay * 1e9)
+
+        PsycopgInstrumentor().uninstrument()