maps: handle empty geojson (#58283)

combo/apps/maps/models.py

@@ -241,6 +241,12 @@ class MapLayer(models.Model):
                 'features': [],
                 '_combo_err_desc': "Non JSON response from requested URL",
             }
+        if data is None:
+            return {
+                'type': 'FeatureCollection',
+                'features': [],
+                '_combo_err_desc': "Empty JSON response",
+            }
         if 'features' in data:
             features = data['features']
         else:

tests/test_maps_cells.py

@@ -304,6 +304,11 @@ def test_get_geojson(app, layer, user):
         assert len(resp.json['features']) == 0
         assert resp.json['_combo_err_desc'] == 'Non JSON response from requested URL'
 
+        mock_resp.json = lambda: None
+        resp = app.get(geojson_url)
+        assert len(resp.json['features']) == 0
+        assert resp.json['_combo_err_desc'] == 'Empty JSON response'
+
         mock_resp.status_code = 500
         resp = app.get(geojson_url)
         assert len(resp.json['features']) == 0