move other resolvers into their own files

src/resolvers/SystemResolvers.ts

@@ -0,0 +1,63 @@
+import { Coordinates, Resolvers } from "../generated/graphql";
+import { ServerContext } from "../ServerContext";
+
+export const SystemResolvers: Resolvers<ServerContext> = {
+  System: {
+    routes: async (parent, args, contextValue, info) => {
+      return await contextValue.repository.getRoutesBySystemId(parent.id);
+    },
+    stops: async (parent, args, contextValue, info) => {
+      const stops = await contextValue.repository.getStopsBySystemId(parent.id);
+      return stops.map(({
+                          id,
+                          name,
+                          coordinates
+                        }) => ({
+        id,
+        name,
+        // Both ICoordinates and Coordinates have the same definition
+        coordinates: coordinates as Coordinates,
+      }));
+    },
+    stop: async (parent, args, contextValue, info) => {
+      if (!args.id) return null;
+      const stop = await contextValue.repository.getStopById(args.id);
+      if (stop === null) return null;
+
+      return {
+        id: stop.id,
+        name: stop.name,
+        coordinates: stop.coordinates as Coordinates,
+      };
+    },
+    route: async (parent, args, contextValue, info) => {
+      if (!args.id) return null;
+      const route = await contextValue.repository.getRouteById(args.id);
+      if (route === null) return null;
+
+      return {
+        color: route.color,
+        id: route.id,
+        name: route.name,
+        polylineCoordinates: route.polylineCoordinates as Coordinates[],
+      };
+    },
+    shuttle: async (parent, args, contextValue, info) => {
+      if (!args.id) return null;
+      const shuttle = await contextValue.repository.getShuttleById(args.id);
+      if (shuttle === null) return null;
+
+      return shuttle;
+    },
+    shuttles: async (parent, args, contextValue, info) => {
+      const shuttles = await contextValue.repository.getShuttlesBySystemId(parent.id);
+
+      return shuttles.map(shuttle => ({
+        coordinates: shuttle.coordinates,
+        name: shuttle.name,
+        id: shuttle.id,
+        routeId: shuttle.routeId,
+      }));
+    }
+  },
+}