fix(mobility_features): distanceTraveled was always 0

packages/mobility_features/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 6.2.1
+
+* Fix `distanceTraveled` always being 0: the path window between two stops ended at the first stop, so every move had an empty path. Falls back to the straight-line distance when no samples are kept (e.g. after a restart).
+
 ## 6.2.0
 
 * upgrade to `carp_serializable` ^3.0.0

packages/mobility_features/lib/mobility_features.dart

@@ -174,6 +174,7 @@ class MobilityFeatures {
     _places.clear();
     _cluster.clear();
     _buffer.clear();
+    _samples.clear();
   }
 
   /// Save a sample to the buffer and store samples on disk if buffer overflows

packages/mobility_features/lib/src/mobility_functions.dart

@@ -48,9 +48,13 @@ List<Move> _findMoves(List<Stop> stops, List<LocationSample> samples) {
       final path = samples
           .where((s) =>
               previous!.dateTime.leq(s.dateTime) &&
-              previous.dateTime.geq(s.dateTime))
+              current.dateTime.geq(s.dateTime))
           .toList();
-      Move m = Move.fromPath(previous, current, path);
+      // No path (samples not kept across restarts) - fall back to the
+      // straight line between the stops rather than reporting 0 m.
+      Move m = path.length > 1
+          ? Move.fromPath(previous, current, path)
+          : Move.fromStops(previous, current);
       moves.add(m);
     }
     previous = current;

packages/mobility_features/pubspec.yaml

@@ -1,6 +1,6 @@
 name: mobility_features
 description: Calculation of real-time mobility features like places, stops, and home stay
-version: 6.2.0
+version: 6.2.1
 homepage: https://github.com/cph-cachet/flutter-plugins/
 
 environment:

packages/mobility_features/test/mobility_features_test.dart

@@ -236,6 +236,11 @@ void main() async {
       void onContext(MobilityContext mc) {
         print(mc.toJson());
         printList(mc.stops!);
+        // Once there is a move, distance is the walked path (~1.5 km home ->
+        // Falkoner Alle), not 0 - the path window must span the two stops.
+        if (mc.numberOfMoves! > 0) {
+          expect(mc.distanceTraveled, greaterThan(1000));
+        }
       }
 
       flushFiles();