Merge pull request #10 from brendan-ch/chore/test-timed-api-based-repository-loader

chore/test-timed-api-based-repository-loader

src/loaders/TimedApiBasedRepositoryLoader.ts

@@ -2,8 +2,6 @@ import { GetterSetterRepository } from "../repositories/GetterSetterRepository";
 import { IEta, IRoute, IShuttle, IStop, ISystem } from "../entities/entities";
 import { ApiBasedRepositoryLoader } from "./ApiBasedRepositoryLoader";
 
-const timeout = 10000;
-
 // Ideas to break this into smaller pieces in the future:
 // Have one repository data loader running for each supported system
 // Each data loader independently updates data based on frequency of usage
@@ -22,6 +20,8 @@ export class TimedApiBasedRepositoryLoader extends ApiBasedRepositoryLoader {
   private shouldBeRunning: boolean = false;
   private timer: any;
 
+  readonly timeout = 10000;
+
   constructor(
     repository: GetterSetterRepository,
   ) {
@@ -61,7 +61,6 @@ export class TimedApiBasedRepositoryLoader extends ApiBasedRepositoryLoader {
       console.error(e);
     }
 
-    this.timer = setTimeout(this.startFetchDataAndUpdate, timeout);
+    this.timer = setTimeout(this.startFetchDataAndUpdate, this.timeout);
   }
-
 }

test/loaders/ApiBasedRepositoryLoaderTests.test.ts

@@ -13,50 +13,16 @@ import {
   fetchShuttleDataSuccessfulResponse
 } from "../jsonSnapshots/fetchShuttleData/fetchShuttleDataSuccessfulResponse";
 import { fetchEtaDataSuccessfulResponse } from "../jsonSnapshots/fetchEtaData/fetchEtaDataSuccessfulResponse";
-
-/**
- * Function to update behavior of the global `fetch` function.
- * Note that the Passio GO API returns status code 200 for failed responses.
- * @param obj
- * @param status
- */
-function updateGlobalFetchMockJson(
-  obj: any,
-  status: number = 200
-) {
-  // @ts-ignore
-  global.fetch = jest.fn(() => {
-    return Promise.resolve({
-      json: () => Promise.resolve(obj),
-      status,
-      ok: status.toString().startsWith("2"), // 200-level codes are OK
-    })
-  }) as jest.Mock;
-}
-
-/**
- * Reset the global fetch function mock's JSON to return an empty object.
- * @param obj
- */
-function resetGlobalFetchMockJson() {
-  updateGlobalFetchMockJson({});
-}
+import {
+  resetGlobalFetchMockJson,
+  updateGlobalFetchMockJson,
+  updateGlobalFetchMockJsonToThrowSyntaxError
+} from "../mockHelpers/fetchMockHelpers";
 
 async function assertAsyncCallbackThrowsApiResponseError(callback: () => Promise<any>) {
   await expect(callback).rejects.toThrow(ApiResponseError);
 }
 
-function updateGlobalFetchMockJsonToThrowSyntaxError() {
-  // @ts-ignore
-  global.fetch = jest.fn(() => {
-    return Promise.resolve({
-      json: () => Promise.reject(new SyntaxError("Unable to parse JSON")),
-      status: 200,
-      ok: true,
-    })
-  }) as jest.Mock;
-}
-
 describe("ApiBasedRepositoryLoader", () => {
   let loader: ApiBasedRepositoryLoader;
 

test/loaders/TimedApiBasedRepositoryLoaderTests.test.ts

@@ -0,0 +1,82 @@
+import { afterEach, beforeAll, beforeEach, describe, expect, it, jest } from "@jest/globals";
+import { TimedApiBasedRepositoryLoader } from "../../src/loaders/TimedApiBasedRepositoryLoader";
+import { resetGlobalFetchMockJson } from "../mockHelpers/fetchMockHelpers";
+import { GetterSetterRepository } from "../../src/repositories/GetterSetterRepository";
+
+describe("TimedApiBasedRepositoryLoader", () => {
+  let repositoryMock: GetterSetterRepository;
+  let loader: TimedApiBasedRepositoryLoader;
+  let spies: any;
+
+  beforeAll(() => {
+    jest.useFakeTimers();
+    jest.spyOn(global, "setTimeout");
+  });
+
+  beforeEach(() => {
+    resetGlobalFetchMockJson();
+
+    repositoryMock = {
+      clearSystemData: jest.fn(),
+      clearRouteData: jest.fn(),
+      clearStopData: jest.fn(),
+      clearShuttleData: jest.fn(),
+      clearEtaData: jest.fn(),
+    } as unknown as GetterSetterRepository;
+
+    loader = new TimedApiBasedRepositoryLoader(repositoryMock);
+
+    spies = {
+      fetchAndUpdateSystemData: jest.spyOn(loader, 'fetchAndUpdateSystemData'),
+      fetchAndUpdateRouteDataForExistingSystemsInRepository: jest.spyOn(loader, 'fetchAndUpdateRouteDataForExistingSystemsInRepository'),
+      fetchAndUpdateStopAndPolylineDataForRoutesInExistingSystemsInRepository: jest.spyOn(loader, 'fetchAndUpdateStopAndPolylineDataForRoutesInExistingSystemsInRepository'),
+      fetchAndUpdateShuttleDataForExistingSystemsInRepository: jest.spyOn(loader, 'fetchAndUpdateShuttleDataForExistingSystemsInRepository'),
+      fetchAndUpdateEtaDataForExistingStopsForSystemsInRepository: jest.spyOn(loader, 'fetchAndUpdateEtaDataForExistingStopsForSystemsInRepository')
+    };
+
+    Object.values(spies).forEach((spy: any) => {
+      spy.mockResolvedValue(undefined);
+    });
+  });
+
+  afterEach(() => {
+    jest.clearAllMocks();
+    jest.clearAllTimers();
+  })
+
+  describe("start", () => {
+    it("should update internal state, call data fetching methods, and start a timer", async () => {
+      await loader.start();
+      expect(loader["shouldBeRunning"]).toBe(true);
+
+      Object.values(repositoryMock).forEach((mockFn) => {
+        expect(mockFn).toHaveBeenCalled();
+      });
+      Object.values(spies).forEach((spy: any) => {
+        expect(spy).toHaveBeenCalled();
+      });
+
+      expect(setTimeout).toHaveBeenCalledWith(expect.any(Function), loader.timeout);
+      expect(loader.timeout).not.toBeUndefined();
+    });
+
+    it("does nothing if timer is already running", async () => {
+      await loader.start();
+      await loader.start();
+
+      Object.values(repositoryMock).forEach((mockFn) => {
+        expect(mockFn).toHaveBeenCalledTimes(1);
+      });
+      Object.values(spies).forEach((spy: any) => {
+        expect(spy).toHaveBeenCalledTimes(1);
+      });
+    });
+  });
+
+  describe("stop", () => {
+    it("should update internal state", async () => {
+      loader.stop();
+      expect(loader['shouldBeRunning']).toBe(false);
+    });
+  });
+});

test/mockHelpers/fetchMockHelpers.ts

@@ -0,0 +1,41 @@
+import { jest } from "@jest/globals";
+
+/**
+ * Function to update behavior of the global `fetch` function.
+ * Note that the Passio GO API returns status code 200 for failed responses.
+ * @param obj
+ * @param status
+ */
+export function updateGlobalFetchMockJson(
+  obj: any,
+  status: number = 200
+) {
+  // @ts-ignore
+  global.fetch = jest.fn(() => {
+    return Promise.resolve({
+      json: () => Promise.resolve(obj),
+      status,
+      ok: status.toString().startsWith("2"), // 200-level codes are OK
+    })
+  });
+}
+
+/**
+ * Reset the global fetch function mock's JSON to return an empty object.
+ * @param obj
+ */
+export function resetGlobalFetchMockJson() {
+  updateGlobalFetchMockJson({});
+}
+
+
+export function updateGlobalFetchMockJsonToThrowSyntaxError() {
+  // @ts-ignore
+  global.fetch = jest.fn(() => {
+    return Promise.resolve({
+      json: () => Promise.reject(new SyntaxError("Unable to parse JSON")),
+      status: 200,
+      ok: true,
+    })
+  }) as jest.Mock;
+}