Develop

Makefile

@@ -60,15 +60,15 @@ frontend:
 	cd $(FRONTEND_DIR) && pnpm dev
 
 export-schema:
-	cd $(BACKEND_DIR) && uv run python export_openapi.py
+	cd $(BACKEND_DIR) && uv run python -m scripts.export_openapi
 
 generate-client: $(OPENAPI_JSON)
 	cd $(FRONTEND_DIR) && pnpm generate-client
 
-openapi: export-schema generate-client
+$(OPENAPI_JSON): $(BACKEND_DIR)/app/main.py $(BACKEND_DIR)/scripts/export_openapi.py
+	cd $(BACKEND_DIR) && uv run python -m scripts.export_openapi
 
-$(OPENAPI_JSON): $(BACKEND_DIR)/app/main.py $(BACKEND_DIR)/export_openapi.py
-	cd $(BACKEND_DIR) && uv run python export_openapi.py
+openapi: export-schema generate-client
 
 install-backend:
 	cd $(BACKEND_DIR) && uv sync

backend/app/route_planner.py

@@ -12,7 +12,6 @@
 from geojson_pydantic import LineString as PydanticLineString
 from geojson_pydantic import Point as PydanticPoint
 from geojson_pydantic.types import Position2D, Position3D
-from networkx.exception import NetworkXNoPath
 
 from app.costs import (
     FALLBACK_EDGE_COST,
@@ -54,6 +53,10 @@
 type NearestNodeFunction = Callable[..., int]
 
 
+class ParetoSearchLimitExceededError(RuntimeError):
+    """Raised when bounded Pareto search exhausts its label budget."""
+
+
 @dataclass(frozen=True, slots=True)
 class RouteCandidate:
     """A fully resolved route candidate ready for response serialization."""
@@ -580,7 +583,12 @@ def _build_pareto_route_candidates(
     )
 
     if not destination_label_ids:
-        raise NetworkXNoPath
+        error_message = (
+            "Bounded Pareto search did not find a destination label before reaching "
+            "the configured label limit."
+        )
+
+        raise ParetoSearchLimitExceededError(error_message)
 
     ranked_label_ids = sorted(
         destination_label_ids,
@@ -826,8 +834,10 @@ def build_route_feature_collection(
             destination_node_id,
             route_options,
         )
-    except NetworkXNoPath:
-        raise HTTPException(status_code=500, detail="No path found.") from None
+    except ParetoSearchLimitExceededError as exception:
+        raise HTTPException(
+            status_code=500, detail=f"Path calculation failed: {exception}"
+        ) from None
     except Exception as exception:  # pragma: no cover - library failure path
         raise HTTPException(
             status_code=500,

backend/notebooks/test.ipynb

@@ -54,15 +54,19 @@
    "cell_type": "code",
    "id": "786fa2b4142c599f",
    "metadata": {},
-   "source": "fig, ax = ox.plot.plot_graph(GRAPH_CYCLING)",
+   "source": [
+    "fig, ax = ox.plot.plot_graph(GRAPH_CYCLING)"
+   ],
    "outputs": [],
    "execution_count": null
   },
   {
    "cell_type": "code",
    "id": "ebb5dc7e6caf7817",
    "metadata": {},
-   "source": "list(GRAPH_CYCLING.edges(keys=True, data=True))[34]",
+   "source": [
+    "list(GRAPH_CYCLING.edges(keys=True, data=True))[34]"
+   ],
    "outputs": [],
    "execution_count": null
   },

backend/pyproject.toml

@@ -19,6 +19,7 @@ dependencies = [
 dev = [
     "basedpyright>=1.38.2",
     "jupyterlab>=4.5.4",
+    "matplotlib>=3.10.9",
     "pytest>=9.0.2",
     "pytest-cov>=7.0.0",
     "ruff>=0.15.0",
@@ -50,7 +51,7 @@ convention = "google"
 
 [tool.basedpyright]
 typeCheckingMode = "all"
-include = ["app", "tests", "export_openapi.py"]
+include = ["app", "tests", "scripts"]
 exclude = ["notebooks"]
 venvPath = "."
 venv = ".venv"

backend/scripts/__init__.py

@@ -0,0 +1 @@
+"""Evaluation scripts."""