Start automated change-detector tests, but keep them disabled, since the

GJ output isn't deterministic right now

Author: dabreegster

backend/src/common/tags.rs

@@ -58,6 +58,8 @@ impl From<HashMap<String, String>> for Tags {
 
 #[cfg(test)]
 mod tests {
+    use super::*;
+
     #[test]
     fn various() {
         let mut tags = Tags::empty();

backend/src/lib.rs

@@ -28,6 +28,8 @@ mod render_cells;
 mod route;
 mod scrape;
 mod shortcuts;
+#[cfg(test)]
+mod tests;
 
 static START: Once = Once::new();
 

backend/src/tests.rs

@@ -0,0 +1,42 @@
+use anyhow::Result;
+use geo::Polygon;
+use geojson::FeatureCollection;
+
+use crate::{MapModel, Neighbourhood};
+
+#[test]
+fn test_bristol_west() {
+    test_example("bristol", "bristol_west", "west");
+}
+
+fn test_example(study_area_name: &str, savefile_name: &str, neighbourhood_name: &str) {
+    let output_path = format!("../tests/output/{savefile_name}.geojson");
+    let expected = std::fs::read_to_string(&output_path).unwrap_or_else(|_| String::new());
+    let actual = get_gj(study_area_name, savefile_name, neighbourhood_name).unwrap();
+
+    if expected != actual {
+        std::fs::write(output_path, actual).unwrap();
+        panic!("{savefile_name} has changed. Manually compare before/after changes with the web UI, then commit the output file to git.");
+    }
+}
+
+// TODO Must run from 'backend'
+// TODO web/public/osm must be symlinked to local PBF copies
+fn get_gj(study_area_name: &str, savefile_name: &str, neighbourhood_name: &str) -> Result<String> {
+    let input_bytes = std::fs::read(format!("../web/public/osm/{study_area_name}.pbf"))?;
+    let mut map = MapModel::new(&input_bytes, Some(study_area_name.to_string()))?;
+
+    let savefile: FeatureCollection =
+        std::fs::read_to_string(format!("../tests/{savefile_name}.geojson"))?.parse()?;
+    map.load_savefile(savefile)?;
+
+    // set_current_neighbourhood equivalent
+    let boundary_gj = map.boundaries.get(neighbourhood_name).cloned().unwrap();
+    let mut boundary_geo: Polygon = boundary_gj.try_into()?;
+    map.mercator.to_mercator_in_place(&mut boundary_geo);
+    let neighbourhood = Neighbourhood::new(&map, neighbourhood_name.to_string(), boundary_geo)?;
+
+    // TODO Include modal filters, once we detect existing ones
+
+    Ok(serde_json::to_string_pretty(&neighbourhood.to_gj(&map))?)
+}

tests/README.md

@@ -1,6 +1,16 @@
 # Test cases
 
-This directory has project files for areas with boundaries that've proven buggy in the past. Eventually, we can also save the neighbourhood GeoJSON dump here too and have automated regression tests. Each file can be loaded from the title screen.
+This directory has project files for areas with boundaries that've proven buggy in the past. Each file can be loaded from the title screen.
+
+The `output` directory has GeoJSON output capturing:
+
+- Roads detected as interior to the neighbourhood
+- Cell boundaries
+- Shortcuts per interior road
+
+The "unit" test in `backend/src/tests.rs` verifies this output doesn't change. When it does, we can manually load the savefile in the old and new web UI, check any differences, and manually approve them.
+
+## Notes per test case
 
 There are several stages of "working" for each of these: