osm_graph 0.1.2

This library provides a set of tools for generating isochrones from geographic coordinates. It leverages OpenStreetMap data to construct road networks and calculate areas accessible within specified time limits. The library is designed for both Rust and Python, offering high performance and easy integration into data science workflows.
Documentation 
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#[cfg(test)]
mod tests {
    use petgraph::graph::DiGraph;

    use crate::graph::{XmlNode, XmlTag, XmlWay, XmlNodeRef};
    use crate::utils::{calculate_distance, calculate_travel_time};
    use crate::overpass::bbox_from_point;

    // --- Helpers ---

    fn make_node(id: i64, lat: f64, lon: f64) -> XmlNode {
        XmlNode { id, lat, lon, tags: vec![], geohash: None }
    }

    fn make_way(id: i64, tags: Vec<(&str, &str)>) -> XmlWay {
        XmlWay {
            id,
            nodes: vec![],
            tags: tags.into_iter().map(|(k, v)| XmlTag {
                key: k.to_string(),
                value: v.to_string(),
            }).collect(),
            length: 100.0,
            speed_kph: 50.0,
            walk_travel_time: 72.0,
            bike_travel_time: 24.0,
            drive_travel_time: 7.2,
        }
    }

    // --- calculate_distance ---

    #[test]
    fn test_distance_same_point() {
        let d = calculate_distance(48.0, 11.0, 48.0, 11.0);
        assert_eq!(d, 0.0);
    }

    #[test]
    fn test_distance_known_value() {
        // Munich to roughly 1km north — should be close to 1000m
        let d = calculate_distance(48.0, 11.0, 48.009, 11.0);
        assert!((d - 1000.0).abs() < 10.0, "Expected ~1000m, got {}", d);
    }

    #[test]
    fn test_distance_is_symmetric() {
        let d1 = calculate_distance(48.0, 11.0, 52.0, 13.0);
        let d2 = calculate_distance(52.0, 13.0, 48.0, 11.0);
        assert!((d1 - d2).abs() < 1e-6);
    }

    // --- calculate_travel_time ---

    #[test]
    fn test_travel_time_basic() {
        // 1000m at 36 kph = 100 seconds
        let t = calculate_travel_time(1000.0, 36.0);
        assert!((t - 100.0).abs() < 1e-6, "Expected 100s, got {}", t);
    }

    #[test]
    fn test_travel_time_walking() {
        // 500m at 5 kph = 360 seconds
        let t = calculate_travel_time(500.0, 5.0);
        assert!((t - 360.0).abs() < 1e-6);
    }

    // --- bbox_from_point ---

    #[test]
    fn test_bbox_is_symmetric() {
        let bbox = bbox_from_point(48.0, 11.0, 1000.0);
        let parts: Vec<f64> = bbox.split(',').map(|s| s.parse().unwrap()).collect();
        let (south, west, north, east) = (parts[0], parts[1], parts[2], parts[3]);
        // Should be symmetric around the origin
        assert!((48.0 - south - (north - 48.0)).abs() < 1e-6);
        assert!((11.0 - west - (east - 11.0)).abs() < 1e-6);
    }

    #[test]
    fn test_bbox_larger_dist_gives_larger_box() {
        let small = bbox_from_point(48.0, 11.0, 1_000.0);
        let large = bbox_from_point(48.0, 11.0, 10_000.0);
        let small_parts: Vec<f64> = small.split(',').map(|s| s.parse().unwrap()).collect();
        let large_parts: Vec<f64> = large.split(',').map(|s| s.parse().unwrap()).collect();
        // north of large should be greater than north of small
        assert!(large_parts[2] > small_parts[2]);
    }

    // --- clean_maxspeed (private, tested via create_graph indirectly) ---
    // We test the observable effect: a way tagged maxspeed=30 should get speed 30.0

    #[test]
    fn test_graph_respects_maxspeed_tag() {
        let nodes = vec![make_node(1, 0.0, 0.0), make_node(2, 0.001, 0.0)];
        let way = XmlWay {
            id: 1,
            nodes: vec![
                XmlNodeRef { node_id: 1 },
                XmlNodeRef { node_id: 2 },
            ],
            tags: vec![
                XmlTag { key: "highway".to_string(), value: "residential".to_string() },
                XmlTag { key: "maxspeed".to_string(), value: "30".to_string() },
            ],
            length: 0.0,
            speed_kph: 0.0,
            walk_travel_time: 0.0,
            bike_travel_time: 0.0,
            drive_travel_time: 0.0,
        };
        let graph = crate::graph::create_graph(vec![nodes[0].clone(), nodes[1].clone()], vec![way], true, false);
        let speed = graph.edge_weights().next().unwrap().speed_kph;
        assert_eq!(speed, 30.0);
    }

    // --- assess_path_directionality (via create_graph edge count) ---

    #[test]
    fn test_oneway_produces_single_edge() {
        let nodes = vec![make_node(1, 0.0, 0.0), make_node(2, 0.001, 0.0)];
        let way = XmlWay {
            id: 1,
            nodes: vec![XmlNodeRef { node_id: 1 }, XmlNodeRef { node_id: 2 }],
            tags: vec![
                XmlTag { key: "highway".to_string(), value: "residential".to_string() },
                XmlTag { key: "oneway".to_string(), value: "yes".to_string() },
            ],
            length: 0.0, speed_kph: 0.0,
            walk_travel_time: 0.0, bike_travel_time: 0.0, drive_travel_time: 0.0,
        };
        let graph = crate::graph::create_graph(vec![nodes[0].clone(), nodes[1].clone()], vec![way], true, false);
        assert_eq!(graph.edge_count(), 1);
    }

    #[test]
    fn test_bidirectional_produces_two_edges() {
        let nodes = vec![make_node(1, 0.0, 0.0), make_node(2, 0.001, 0.0)];
        let way = XmlWay {
            id: 1,
            nodes: vec![XmlNodeRef { node_id: 1 }, XmlNodeRef { node_id: 2 }],
            tags: vec![
                XmlTag { key: "highway".to_string(), value: "residential".to_string() },
            ],
            length: 0.0, speed_kph: 0.0,
            walk_travel_time: 0.0, bike_travel_time: 0.0, drive_travel_time: 0.0,
        };
        let graph = crate::graph::create_graph(vec![nodes[0].clone(), nodes[1].clone()], vec![way], true, false);
        assert_eq!(graph.edge_count(), 2);
    }

    // --- deduplicate_edges ---

    #[test]
    fn test_deduplicate_keeps_fastest_edge() {
        let mut graph = DiGraph::new();
        let a = graph.add_node(make_node(1, 0.0, 0.0));
        let b = graph.add_node(make_node(2, 0.001, 0.0));

        let mut slow = make_way(1, vec![]);
        slow.drive_travel_time = 100.0;
        let mut fast = make_way(2, vec![]);
        fast.drive_travel_time = 50.0;

        graph.add_edge(a, b, slow);
        graph.add_edge(a, b, fast);

        // Access deduplicate_edges via simplify_graph on a graph that already has only endpoints
        // Instead test the observable: after simplification parallel edges are gone
        assert_eq!(graph.edge_count(), 2); // before
        let deduped = crate::simplify::simplify_graph(&graph);
        // Only one edge should remain between any two nodes
        let edge_count = deduped.edge_count();
        assert!(edge_count <= 1, "Expected at most 1 edge, got {}", edge_count);
    }

    // --- SpatialGraph nearest_node ---

    #[test]
    fn test_nearest_node_finds_closest() {
        let mut graph = DiGraph::new();
        graph.add_node(make_node(1, 48.0, 11.0));
        graph.add_node(make_node(2, 52.0, 13.0)); // Berlin-ish
        let sg = crate::graph::SpatialGraph::new(graph);
        // Query close to Munich node
        let idx = sg.nearest_node(48.001, 11.001).unwrap();
        let node = &sg.graph[idx];
        assert_eq!(node.id, 1);
    }
}