From ecdba0447682e196020896bcf93a357672f75e97 Mon Sep 17 00:00:00 2001
From: Phani Kumar <phani.kumar@astronomer.io>
Date: Fri, 28 Apr 2023 15:19:09 +0530
Subject: [PATCH] optimize deferred execution for
 GCSObjectsWithPrefixExistenceSensor

---
 airflow/providers/google/cloud/sensors/gcs.py | 27 ++++++++++---------
 .../google/cloud/sensors/test_gcs.py          | 22 ++++++++++++---
 2 files changed, 33 insertions(+), 16 deletions(-)

diff --git a/airflow/providers/google/cloud/sensors/gcs.py b/airflow/providers/google/cloud/sensors/gcs.py
index d346c5303b53b..de2a433fbf1c9 100644
--- a/airflow/providers/google/cloud/sensors/gcs.py
+++ b/airflow/providers/google/cloud/sensors/gcs.py
@@ -323,19 +323,20 @@ def execute(self, context: Context):
             super().execute(context)
             return self._matches
         else:
-            self.defer(
-                timeout=timedelta(seconds=self.timeout),
-                trigger=GCSPrefixBlobTrigger(
-                    bucket=self.bucket,
-                    prefix=self.prefix,
-                    poke_interval=self.poke_interval,
-                    google_cloud_conn_id=self.google_cloud_conn_id,
-                    hook_params={
-                        "impersonation_chain": self.impersonation_chain,
-                    },
-                ),
-                method_name="execute_complete",
-            )
+            if not self.poke(context=context):
+                self.defer(
+                    timeout=timedelta(seconds=self.timeout),
+                    trigger=GCSPrefixBlobTrigger(
+                        bucket=self.bucket,
+                        prefix=self.prefix,
+                        poke_interval=self.poke_interval,
+                        google_cloud_conn_id=self.google_cloud_conn_id,
+                        hook_params={
+                            "impersonation_chain": self.impersonation_chain,
+                        },
+                    ),
+                    method_name="execute_complete",
+                )
 
     def execute_complete(self, context: dict[str, Any], event: dict[str, str | list[str]]) -> str | list[str]:
         """
diff --git a/tests/providers/google/cloud/sensors/test_gcs.py b/tests/providers/google/cloud/sensors/test_gcs.py
index b23a28e238ecb..0299898b661a3 100644
--- a/tests/providers/google/cloud/sensors/test_gcs.py
+++ b/tests/providers/google/cloud/sensors/test_gcs.py
@@ -369,6 +369,21 @@ def test_execute_timeout(self, mock_hook):
             task.execute(mock.MagicMock)
             mock_hook.return_value.list.assert_called_once_with(TEST_BUCKET, prefix=TEST_PREFIX)
 
+    @mock.patch("airflow.providers.google.cloud.sensors.gcs.GCSHook")
+    @mock.patch("airflow.providers.google.cloud.sensors.gcs.GCSObjectsWithPrefixExistenceSensor.defer")
+    def test_gcs_object_prefix_existence_sensor_finish_before_deferred(self, mock_defer, mock_hook):
+        task = GCSObjectsWithPrefixExistenceSensor(
+            task_id="task-id",
+            bucket=TEST_BUCKET,
+            prefix=TEST_PREFIX,
+            google_cloud_conn_id=TEST_GCP_CONN_ID,
+            impersonation_chain=TEST_IMPERSONATION_CHAIN,
+            deferrable=True,
+        )
+        mock_hook.return_value.list.return_value = True
+        task.execute(mock.MagicMock())
+        assert not mock_defer.called
+
 
 class TestGCSObjectsWithPrefixExistenceSensorAsync:
     OPERATOR = GCSObjectsWithPrefixExistenceSensor(
@@ -379,14 +394,15 @@ class TestGCSObjectsWithPrefixExistenceSensorAsync:
         deferrable=True,
     )
 
-    def test_gcs_object_with_prefix_existence_sensor_async(self, context):
+    @mock.patch("airflow.providers.google.cloud.sensors.gcs.GCSHook")
+    def test_gcs_object_with_prefix_existence_sensor_async(self, mock_hook):
         """
         Asserts that a task is deferred and a GCSPrefixBlobTrigger will be fired
         when the GCSObjectsWithPrefixExistenceSensorAsync is executed.
         """
-
+        mock_hook.return_value.list.return_value = False
         with pytest.raises(TaskDeferred) as exc:
-            self.OPERATOR.execute(context)
+            self.OPERATOR.execute(mock.MagicMock())
         assert isinstance(exc.value.trigger, GCSPrefixBlobTrigger), "Trigger is not a GCSPrefixBlobTrigger"
 
     def test_gcs_object_with_prefix_existence_sensor_async_execute_failure(self, context):