add test case for nextStop resolver for ordered stop

test/resolvers/OrderedStopResolverTests.test.ts

@@ -1,23 +1,30 @@
-import { beforeEach, describe, it } from "@jest/globals";
+import { beforeEach, describe, expect, it } from "@jest/globals";
 import { ApolloServer } from "@apollo/server";
 import { UnoptimizedInMemoryRepository } from "../../src/repositories/UnoptimizedInMemoryRepository";
 import { ServerContext } from "../../src/ServerContext";
 import { setUpTestServer } from "../testHelpers/apolloSetupHelpers";
 import { IRoute, IStop, ISystem } from "../../src/entities/entities";
-import { generateMockRoutes, generateMockShuttles, generateMockStops, generateMockSystems } from "../generators";
+import {
+  generateMockOrderedStops,
+  generateMockRoutes,
+  generateMockShuttles,
+  generateMockStops,
+  generateMockSystems
+} from "../generators";
+import assert = require("node:assert");
 
 describe("OrderedStopResolvers", () => {
-  let apolloServer: ApolloServer<ServerContext>;
+  let testServer: ApolloServer<ServerContext>;
   let repository: UnoptimizedInMemoryRepository;
 
   beforeEach(async () => {
-    apolloServer = setUpTestServer();
+    testServer = setUpTestServer();
     repository = new UnoptimizedInMemoryRepository();
   });
 
   let mockSystem: ISystem;
   let mockRoute: IRoute;
-  let mockStop: IStop;
+  let mockStops: IStop[];
 
   beforeEach(async () => {
     const mockSystems = generateMockSystems();
@@ -30,10 +37,11 @@ describe("OrderedStopResolvers", () => {
     mockRoute.id = "1";
     await repository.addOrUpdateRoute(mockRoute);
 
-    const mockStops = generateMockStops();
-    mockStop = mockStops[0];
-    mockStop.id = "1";
-    await repository.addOrUpdateStop(mockStop);
+    mockStops = generateMockStops();
+
+    await Promise.all(mockStops.map(async (mockStop) => {
+      await repository.addOrUpdateStop(mockStop);
+    }));
   });
 
   describe("nextStop", () => {
@@ -53,7 +61,44 @@ describe("OrderedStopResolvers", () => {
     `;
 
     it("returns the next stop if it exists", async () => {
+      // Arrange
+      const orderedStops = generateMockOrderedStops();
 
+      // Set up IDs and link stops together to work with the test query
+      orderedStops[0].routeId = mockRoute.id;
+      orderedStops[1].routeId = mockRoute.id;
+
+      // Ensure that there is no duplication
+      orderedStops[0].stopId = mockStops[0].id;
+      orderedStops[1].stopId = mockStops[1].id;
+
+      // Link the stops together
+      orderedStops[0].nextStop = orderedStops[1];
+      orderedStops[1].previousStop = orderedStops[0];
+      await repository.addOrUpdateOrderedStop(orderedStops[0]);
+      await repository.addOrUpdateOrderedStop(orderedStops[1]);
+
+      // Act
+      const response = await testServer.executeOperation({
+        query,
+        variables: {
+          systemId: mockSystem.id,
+          routeId: mockRoute.id,
+          stopId: orderedStops[0].stopId,
+        }
+      }, {
+        contextValue: {
+          repository,
+        }
+      });
+
+      // Assert
+      assert(response.body.kind === "single");
+      expect(response.body.singleResult.errors).toBeUndefined();
+
+      const nextStop = (response.body.singleResult.data?.system as any).route.orderedStop.nextStop;
+      expect(nextStop.stopId).toEqual(orderedStops[1].stopId);
+      expect(nextStop.routeId).toEqual(orderedStops[1].routeId);
     });
 
     it("returns null if there is no next stop in the repository", async () => {