fix latest dataset filtering

Author: davidgamez

api/src/feeds/impl/datasets_api_impl.py

@@ -50,7 +50,8 @@ def get_datasets_gtfs(query: Query, session: Session, limit: int = None, offset:
             offset=offset,
             group_by=lambda x: x[0].stable_id,
         )
-
+        if not dataset_groups:
+            return []
         gtfs_datasets = []
         for dataset_group in dataset_groups:
             dataset_objects: Tuple[Gtfsdataset, ...]

api/src/feeds/impl/feeds_api_impl.py

@@ -183,7 +183,7 @@ def get_gtfs_feed_datasets(
         ).filter(DatasetsApiImpl.create_dataset_query().filter(FeedOrm.stable_id == gtfs_feed_id))
 
         if latest:
-            query = query.join(Gtfsdataset.feed).filter(Gtfsdataset.id == FeedOrm.latest_dataset_id)
+            query = query.join(Gtfsfeed, Gtfsfeed.latest_dataset_id == Gtfsdataset.id)
 
         return DatasetsApiImpl.get_datasets_gtfs(query, session=db_session, limit=limit, offset=offset)
 

api/tests/integration/test_datasets_api.py

@@ -39,6 +39,28 @@ def test_feeds_gtfs_id_datasets_get(client: TestClient):
     assert response.status_code == 200
 
 
+def test_feeds_gtfs_datasets_latest_get(client: TestClient):
+    """Test case for feeds_gtfs_id_datasets_get"""
+    params = [
+        ("latest", True),
+        ("limit", 10),
+        ("offset", 0),
+        ("filter", "status=active"),
+        ("sort", "+provider"),
+    ]
+    response = client.request(
+        "GET",
+        "/v1/gtfs_feeds/{id}/datasets".format(id=TEST_GTFS_FEED_STABLE_IDS[0]),
+        headers=authHeaders,
+        params=params,
+    )
+
+    assert response.status_code == 200
+    json_response = response.json()
+    assert len(json_response) == 1, "Expected only the latest datasets"
+    assert json_response[0]["id"] == TEST_DATASET_STABLE_IDS[1]  # dataset-2
+
+
 def test_feeds_wrong_gtfs_id_datasets_get(client: TestClient):
     """Test case for feeds_gtfs_id_datasets_get where the gtfs feed id does not exist"""