add shuttles resolver on route

src/resolvers.ts

@@ -88,6 +88,20 @@ export const resolvers: Resolvers<ServerContext> = {
     }
   },
   Route: {
+    shuttles: async (parent, args, contextValue, info) => {
+      const shuttles = await contextValue.repository.getShuttlesByRouteId(parent.id);
+
+      return shuttles.map(({
+        coordinates,
+        name,
+        id,
+      }) => ({
+        coordinates: coordinates as Coordinates,
+        name,
+        route: parent,
+        id,
+      }));
+    }
   },
   Shuttle: {
     eta: (parent, args, contextValue, info) => {