map: don't fail on invalid geojson data (#53521)

combo/apps/maps/models.py

@@ -226,8 +226,19 @@ class MapLayer(models.Model):
             headers={'accept': 'application/json'},
         )
         if not response.ok:
-            return []
-        data = response.json()
+            return {
+                'type': 'FeatureCollection',
+                'features': [],
+                '_combo_err_desc': "Bad status code from requested URL",
+            }
+        try:
+            data = response.json()
+        except json.JSONDecodeError:
+            return {
+                'type': 'FeatureCollection',
+                'features': [],
+                '_combo_err_desc': "Non JSON response from requested URL",
+            }
         if 'features' in data:
             features = data['features']
         else:

tests/test_maps_cells.py

@@ -7,6 +7,7 @@ from django.conf import settings
 from django.contrib.auth.models import Group, User
 from django.test.client import RequestFactory
 from django.urls import reverse
+from requests.models import Response
 
 from combo.apps.maps.models import Map, MapLayer, MapLayerOptions
 from combo.data.models import Page
@@ -284,6 +285,20 @@ def test_get_geojson(app, layer, user):
 
     geojson_url = reverse('mapcell-geojson', kwargs={'cell_id': cell.id, 'layer_slug': layer.slug})
 
+    # invalid content
+    with mock.patch('combo.utils.requests_wrapper.RequestsSession.get') as requests_get:
+        mock_resp = Response()
+        mock_resp.status_code = 200
+        requests_get.return_value = mock_resp
+        resp = app.get(geojson_url)
+        assert len(resp.json['features']) == 0
+        assert resp.json['_combo_err_desc'] == 'Non JSON response from requested URL'
+
+        mock_resp.status_code = 500
+        resp = app.get(geojson_url)
+        assert len(resp.json['features']) == 0
+        assert resp.json['_combo_err_desc'] == 'Bad status code from requested URL'
+
     # check cache duration
     with mock.patch('combo.utils.requests_wrapper.RequestsSession.request') as requests_get:
         requests_get.return_value = mock.Mock(