Fixed route line building

src/directions/utils.ts

@@ -207,17 +207,21 @@ export function buildRoutelines(
 
     // indices of coordinate pairs that match existing snappoints (except for the first one)
     const snappointsCoordinatesIndices = snappointsCoordinates
-      .map((snappointLngLat) => {
+      .map((snappointLngLat, index) => {
         // use the currentIndex to start the search from the place where the last snappoint's coordinate was found
         const waypointCoordinatesIndex = coordinates.slice(currentIndex).findIndex((lngLat) => {
           // there might be an error in 0.00001 degree between snappoint and decoded coordinate when using the
           // "polyline" geometries. The comparator neglects that
           return coordinatesComparator(requestOptions, lngLat, snappointLngLat as [number, number]);
         });
 
+        const isLast = index === snappointsCoordinates.length - 1;
+
         // update the current index if something's found
         if (waypointCoordinatesIndex !== -1) {
           currentIndex += waypointCoordinatesIndex;
+        } else if (isLast) {
+          return coordinates.length - 1;
         }
 
         return currentIndex;