move other resolvers into their own files

src/resolvers/ShuttleResolvers.ts

@@ -0,0 +1,52 @@
+import { Eta, Resolvers } from "../generated/graphql";
+import { ServerContext } from "../ServerContext";
+
+export const ShuttleResolvers: Resolvers<ServerContext> = {
+  Shuttle: {
+    eta: async (parent, args, contextValue, info) => {
+      if (!args.forStopId) return null;
+      const etaForStopId = await contextValue.repository.getEtaForShuttleAndStopId(parent.id, args.forStopId);
+      if (etaForStopId === null) return null;
+
+      return {
+        stopId: args.forStopId,
+        secondsRemaining: etaForStopId.secondsRemaining,
+        shuttleId: parent.id,
+        shuttle: parent,
+      };
+    },
+    etas: async (parent, args, contextValue, info) => {
+      const etasForShuttle = await contextValue.repository.getEtasForShuttleId(parent.id);
+      if (!etasForShuttle) return null;
+
+      const computedEtas = await Promise.all(etasForShuttle.map(async ({
+                                                                         secondsRemaining,
+                                                                         stopId,
+                                                                       }): Promise<Eta | null> => {
+        return {
+          secondsRemaining,
+          stopId,
+          shuttle: parent,
+          shuttleId: parent.id,
+        }
+      }));
+
+      if (computedEtas.every((eta) => eta !== null)) {
+        return computedEtas;
+      }
+
+      return [];
+    },
+    route: async (parent, args, contextValue, info) => {
+      const route = await contextValue.repository.getRouteById(parent.routeId);
+      if (route === null) return null;
+
+      return {
+        color: route.color,
+        id: route.id,
+        name: route.name,
+        polylineCoordinates: route.polylineCoordinates,
+      }
+    }
+  },
+}