Merge branch 'main' into experimenter_bug

swmmanywhere/prepare_data.py

@@ -123,10 +123,18 @@ def download_river(bbox: tuple[float, float, float, float]) -> nx.MultiDiGraph:
             ``truncate_by_edge set`` to True.
     """
     west, south, east, north = bbox
-    graph = ox.graph_from_bbox(
-        bbox = (north, south, east, west),
-        truncate_by_edge=True, 
-        custom_filter='["waterway"]')
+    try: 
+        graph = ox.graph_from_bbox(
+            bbox = (north, south, east, west),
+            truncate_by_edge=True, 
+            custom_filter='["waterway"]',
+            retain_all=True)
+    except ValueError as e:
+        if str(e) == "Found no graph nodes within the requested polygon":
+            logger.warning('No water network found within the bounding box.')
+            return nx.MultiDiGraph()
+        else:
+            raise  # Re-raise the exception 
 
     return cast("nx.MultiDiGraph", graph)
 

tests/test_prepare_data.py

@@ -186,12 +186,22 @@ def test_river_downloader():
     bbox = (0.0402, 51.55759, 0.09825591114207548, 51.6205)
 
     mock_graph = nx.MultiDiGraph()
+    mock_graph.add_node(1)
     # Mock ox.graph_from_bbox
-    with mock.patch.object(ox, 'graph_from_bbox', return_value=mock_graph):
+    with mock.patch.object(ox, 
+                           'graph_from_bbox', 
+                           return_value=mock_graph) as mock_from_bbox:
         # Call download_street
         G = downloaders.download_river(bbox)
         assert G == mock_graph
 
+        mock_from_bbox.side_effect = ValueError(
+            "Found no graph nodes within the requested polygon"
+            )
+        G = downloaders.download_river(bbox)
+        assert G.size() == 0
+
+
 def test_elevation_downloader():
     """Check elevation downloads, writes, contains data, and a known elevation."""
     # Please do not reuse api_key