Merge pull request #17

feat/notification-service

.env.example

@@ -0,0 +1,4 @@
+APNS_KEY_ID=
+APNS_TEAM_ID=
+APNS_BUNDLE_ID=
+APNS_KEY_PATH=

package-lock.json

@@ -9,7 +9,9 @@
       "version": "1.0.0",
       "dependencies": {
         "@apollo/server": "^4.11.2",
-        "graphql": "^16.10.0"
+        "@types/jsonwebtoken": "^9.0.8",
+        "graphql": "^16.10.0",
+        "jsonwebtoken": "^9.0.2"
       },
       "devDependencies": {
         "@graphql-codegen/cli": "5.0.3",
@@ -3565,6 +3567,15 @@
       "integrity": "sha512-k4MGaQl5TGo/iipqb2UDG2UwjXziSWkh0uysQelTlJpX1qGlpUZYm8PnO4DxG1qBomtJUdYJ6qR6xdIah10JLg==",
       "dev": true
     },
+    "node_modules/@types/jsonwebtoken": {
+      "version": "9.0.8",
+      "resolved": "https://registry.npmjs.org/@types/jsonwebtoken/-/jsonwebtoken-9.0.8.tgz",
+      "integrity": "sha512-7fx54m60nLFUVYlxAB1xpe9CBWX2vSrk50Y6ogRJ1v5xxtba7qXTg5BgYDN5dq+yuQQ9HaVlHJyAAt1/mxryFg==",
+      "dependencies": {
+        "@types/ms": "*",
+        "@types/node": "*"
+      }
+    },
     "node_modules/@types/long": {
       "version": "4.0.2",
       "resolved": "https://registry.npmjs.org/@types/long/-/long-4.0.2.tgz",
@@ -3575,6 +3586,11 @@
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       "integrity": "sha512-/pyBZWSLD2n0dcHE3hq8s8ZvcETHtEuF+3E7XVt0Ig2nvsVQXdghHVcEkIWjy9A0wKfTn97a/PSDYohKIlnP/w=="
     },
+    "node_modules/@types/ms": {
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/@types/ms/-/ms-2.1.0.tgz",
+      "integrity": "sha512-GsCCIZDE/p3i96vtEqx+7dBUGXrc7zeSK3wwPHIaRThS+9OhWIXRqzs4d6k1SVU8g91DrNRWxWUGhp5KXQb2VA=="
+    },
     "node_modules/@types/node": {
       "version": "22.10.2",
       "resolved": "https://registry.npmjs.org/@types/node/-/node-22.10.2.tgz",
@@ -4173,6 +4189,11 @@
         "ieee754": "^1.1.13"
       }
     },
+    "node_modules/buffer-equal-constant-time": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/buffer-equal-constant-time/-/buffer-equal-constant-time-1.0.1.tgz",
+      "integrity": "sha512-zRpUiDwd/xk6ADqPMATG8vc9VPrkck7T07OIx0gnjmJAnHnTVXNQG3vfvWNuiZIkwu9KrKdA1iJKfsfTVxE6NA=="
+    },
     "node_modules/buffer-from": {
       "version": "1.1.2",
       "resolved": "https://registry.npmjs.org/buffer-from/-/buffer-from-1.1.2.tgz",
@@ -4863,6 +4884,14 @@
         "node": ">= 0.4"
       }
     },
+    "node_modules/ecdsa-sig-formatter": {
+      "version": "1.0.11",
+      "resolved": "https://registry.npmjs.org/ecdsa-sig-formatter/-/ecdsa-sig-formatter-1.0.11.tgz",
+      "integrity": "sha512-nagl3RYrbNv6kQkeJIpt6NJZy8twLB/2vtz6yN9Z4vRKHN4/QZJIEbqohALSgwKdnksuY3k5Addp5lg8sVoVcQ==",
+      "dependencies": {
+        "safe-buffer": "^5.0.1"
+      }
+    },
     "node_modules/ee-first": {
       "version": "1.1.1",
       "resolved": "https://registry.npmjs.org/ee-first/-/ee-first-1.1.1.tgz",
@@ -6895,6 +6924,62 @@
         "node": ">=6"
       }
     },
+    "node_modules/jsonwebtoken": {
+      "version": "9.0.2",
+      "resolved": "https://registry.npmjs.org/jsonwebtoken/-/jsonwebtoken-9.0.2.tgz",
+      "integrity": "sha512-PRp66vJ865SSqOlgqS8hujT5U4AOgMfhrwYIuIhfKaoSCZcirrmASQr8CX7cUg+RMih+hgznrjp99o+W4pJLHQ==",
+      "dependencies": {
+        "jws": "^3.2.2",
+        "lodash.includes": "^4.3.0",
+        "lodash.isboolean": "^3.0.3",
+        "lodash.isinteger": "^4.0.4",
+        "lodash.isnumber": "^3.0.3",
+        "lodash.isplainobject": "^4.0.6",
+        "lodash.isstring": "^4.0.1",
+        "lodash.once": "^4.0.0",
+        "ms": "^2.1.1",
+        "semver": "^7.5.4"
+      },
+      "engines": {
+        "node": ">=12",
+        "npm": ">=6"
+      }
+    },
+    "node_modules/jsonwebtoken/node_modules/ms": {
+      "version": "2.1.3",
+      "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.3.tgz",
+      "integrity": "sha512-6FlzubTLZG3J2a/NVCAleEhjzq5oxgHyaCU9yYXvcLsvoVaHJq/s5xXI6/XXP6tz7R9xAOtHnSO/tXtF3WRTlA=="
+    },
+    "node_modules/jsonwebtoken/node_modules/semver": {
+      "version": "7.7.0",
+      "resolved": "https://registry.npmjs.org/semver/-/semver-7.7.0.tgz",
+      "integrity": "sha512-DrfFnPzblFmNrIZzg5RzHegbiRWg7KMR7btwi2yjHwx06zsUbO5g613sVwEV7FTwmzJu+Io0lJe2GJ3LxqpvBQ==",
+      "bin": {
+        "semver": "bin/semver.js"
+      },
+      "engines": {
+        "node": ">=10"
+      }
+    },
+    "node_modules/jwa": {
+      "version": "1.4.1",
+      "resolved": "https://registry.npmjs.org/jwa/-/jwa-1.4.1.tgz",
+      "integrity": "sha512-qiLX/xhEEFKUAJ6FiBMbes3w9ATzyk5W7Hvzpa/SLYdxNtng+gcurvrI7TbACjIXlsJyr05/S1oUhZrc63evQA==",
+      "dependencies": {
+        "buffer-equal-constant-time": "1.0.1",
+        "ecdsa-sig-formatter": "1.0.11",
+        "safe-buffer": "^5.0.1"
+      }
+    },
+    "node_modules/jws": {
+      "version": "3.2.2",
+      "resolved": "https://registry.npmjs.org/jws/-/jws-3.2.2.tgz",
+      "integrity": "sha512-YHlZCB6lMTllWDtSPHz/ZXTsi8S00usEV6v1tjq8tOUZzw7DpSDWVXjXDre6ed1w/pd495ODpHZYSdkRTsa0HA==",
+      "dependencies": {
+        "jwa": "^1.4.1",
+        "safe-buffer": "^5.0.1"
+      }
+    },
     "node_modules/kleur": {
       "version": "3.0.3",
       "resolved": "https://registry.npmjs.org/kleur/-/kleur-3.0.3.tgz",
@@ -6981,12 +7066,47 @@
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       "dev": true
     },
+    "node_modules/lodash.includes": {
+      "version": "4.3.0",
+      "resolved": "https://registry.npmjs.org/lodash.includes/-/lodash.includes-4.3.0.tgz",
+      "integrity": "sha512-W3Bx6mdkRTGtlJISOvVD/lbqjTlPPUDTMnlXZFnVwi9NKJ6tiAk6LVdlhZMm17VZisqhKcgzpO5Wz91PCt5b0w=="
+    },
+    "node_modules/lodash.isboolean": {
+      "version": "3.0.3",
+      "resolved": "https://registry.npmjs.org/lodash.isboolean/-/lodash.isboolean-3.0.3.tgz",
+      "integrity": "sha512-Bz5mupy2SVbPHURB98VAcw+aHh4vRV5IPNhILUCsOzRmsTmSQ17jIuqopAentWoehktxGd9e/hbIXq980/1QJg=="
+    },
+    "node_modules/lodash.isinteger": {
+      "version": "4.0.4",
+      "resolved": "https://registry.npmjs.org/lodash.isinteger/-/lodash.isinteger-4.0.4.tgz",
+      "integrity": "sha512-DBwtEWN2caHQ9/imiNeEA5ys1JoRtRfY3d7V9wkqtbycnAmTvRRmbHKDV4a0EYc678/dia0jrte4tjYwVBaZUA=="
+    },
+    "node_modules/lodash.isnumber": {
+      "version": "3.0.3",
+      "resolved": "https://registry.npmjs.org/lodash.isnumber/-/lodash.isnumber-3.0.3.tgz",
+      "integrity": "sha512-QYqzpfwO3/CWf3XP+Z+tkQsfaLL/EnUlXWVkIk5FUPc4sBdTehEqZONuyRt2P67PXAk+NXmTBcc97zw9t1FQrw=="
+    },
+    "node_modules/lodash.isplainobject": {
+      "version": "4.0.6",
+      "resolved": "https://registry.npmjs.org/lodash.isplainobject/-/lodash.isplainobject-4.0.6.tgz",
+      "integrity": "sha512-oSXzaWypCMHkPC3NvBEaPHf0KsA5mvPrOPgQWDsbg8n7orZ290M0BmC/jgRZ4vcJ6DTAhjrsSYgdsW/F+MFOBA=="
+    },
+    "node_modules/lodash.isstring": {
+      "version": "4.0.1",
+      "resolved": "https://registry.npmjs.org/lodash.isstring/-/lodash.isstring-4.0.1.tgz",
+      "integrity": "sha512-0wJxfxH1wgO3GrbuP+dTTk7op+6L41QCXbGINEmD+ny/G/eCqGzxyCsh7159S+mgDDcoarnBw6PC1PS5+wUGgw=="
+    },
     "node_modules/lodash.memoize": {
       "version": "4.1.2",
       "resolved": "https://registry.npmjs.org/lodash.memoize/-/lodash.memoize-4.1.2.tgz",
       "integrity": "sha512-t7j+NzmgnQzTAYXcsHYLgimltOV1MXHtlOWf6GjL9Kj8GK5FInw5JotxvbOs+IvV1/Dzo04/fCGfLVs7aXb4Ag==",
       "dev": true
     },
+    "node_modules/lodash.once": {
+      "version": "4.1.1",
+      "resolved": "https://registry.npmjs.org/lodash.once/-/lodash.once-4.1.1.tgz",
+      "integrity": "sha512-Sb487aTOCr9drQVL8pIxOzVhafOjZN9UU54hiN8PU3uAiSV7lx1yYNpbNmex2PK6dSJoNTSJUUswT651yww3Mg=="
+    },
     "node_modules/lodash.sortby": {
       "version": "4.7.0",
       "resolved": "https://registry.npmjs.org/lodash.sortby/-/lodash.sortby-4.7.0.tgz",

package.json

@@ -19,11 +19,13 @@
     "@types/node": "^22.10.2",
     "jest": "^29.7.0",
     "ts-jest": "^29.2.5",
-    "typescript": "^5.7.2"
+    "typescript": "^5.7.2",
+    "@types/jsonwebtoken": "^9.0.8"
   },
   "private": true,
   "dependencies": {
     "@apollo/server": "^4.11.2",
-    "graphql": "^16.10.0"
+    "graphql": "^16.10.0",
+    "jsonwebtoken": "^9.0.2"
   }
 }

src/services/NotificationService.ts

@@ -0,0 +1,227 @@
+import { GetterRepository } from "../repositories/GetterRepository";
+import jwt from "jsonwebtoken";
+import fs from "fs";
+import { TupleKey } from "../types/TupleKey";
+import { IEta } from "../entities/entities";
+
+export interface ScheduledNotificationData {
+  deviceId: string;
+  shuttleId: string;
+  stopId: string;
+}
+
+export class NotificationService {
+  public readonly secondsThresholdForNotificationToFire = 300;
+
+  private apnsToken: string | undefined = undefined;
+
+  private _lastRefreshedTimeMs: number | undefined = undefined;
+  get lastRefreshedTimeMs() {
+    return this._lastRefreshedTimeMs;
+  }
+
+  constructor(private repository: GetterRepository) {
+    this.etaSubscriberCallback = this.etaSubscriberCallback.bind(this);
+    this.reloadAPNsTokenIfTimePassed = this.reloadAPNsTokenIfTimePassed.bind(this);
+    this.lastReloadedTimeForAPNsIsTooRecent = this.lastReloadedTimeForAPNsIsTooRecent.bind(this);
+    this.sendEtaNotificationImmediately = this.sendEtaNotificationImmediately.bind(this);
+    this.etaSubscriberCallback = this.etaSubscriberCallback.bind(this);
+    this.sendEtaNotificationImmediatelyIfSecondsRemainingBelowThreshold = this.sendEtaNotificationImmediatelyIfSecondsRemainingBelowThreshold.bind(this);
+    this.scheduleNotification = this.scheduleNotification.bind(this);
+  }
+
+  /**
+   * An object of device ID arrays to deliver notifications to.
+   * The key should be a combination of the shuttle ID and
+   * stop ID, which can be generated using `TupleKey`.
+   * @private
+   */
+  private deviceIdsToDeliverTo: { [key: string]: string[] } = {}
+
+  public reloadAPNsTokenIfTimePassed() {
+    if (this.lastReloadedTimeForAPNsIsTooRecent()) {
+      return;
+    }
+
+    const keyId = process.env.APNS_KEY_ID;
+    const teamId = process.env.APNS_TEAM_ID;
+    const privateKeyPath = process.env.APNS_KEY_PATH;
+    if (!privateKeyPath) return;
+    const privateKey = fs.readFileSync(privateKeyPath);
+
+    const tokenHeader = {
+      alg: "ES256",
+      "kid": keyId,
+    };
+
+    const now = Date.now();
+    const claimsPayload = {
+      "iss": teamId,
+      "iat": now,
+    };
+
+    this.apnsToken = jwt.sign(claimsPayload, privateKey, {
+      algorithm: "ES256",
+      header: tokenHeader
+    });
+    this._lastRefreshedTimeMs = now;
+  }
+
+  private lastReloadedTimeForAPNsIsTooRecent() {
+    const thirtyMinutesMs = 1800000;
+    return this._lastRefreshedTimeMs && Date.now() - this._lastRefreshedTimeMs < thirtyMinutesMs;
+  }
+
+  private async sendEtaNotificationImmediately(notificationData: ScheduledNotificationData): Promise<boolean> {
+    const { deviceId, shuttleId, stopId } = notificationData;
+    this.reloadAPNsTokenIfTimePassed();
+    const url = NotificationService.getAPNsFullUrlToUse(deviceId);
+
+    const shuttle = await this.repository.getShuttleById(shuttleId);
+    const stop = await this.repository.getStopById(stopId);
+    const eta = await this.repository.getEtaForShuttleAndStopId(shuttleId, stopId);
+    if (!shuttle) {
+      console.warn(`Notification ${notificationData} fell through; no associated shuttle`);
+      return false;
+    }
+    if (!stop) {
+      console.warn(`Notification ${notificationData} fell through; no associated stop`);
+      return false;
+    }
+
+    // Notification may not be sent if ETA is unavailable at the moment;
+    // this is fine because it will be sent again when ETA becomes available
+    if (!eta) {
+      console.warn(`Notification ${notificationData} fell through; no associated ETA`);
+      return false;
+    }
+
+    // Send the fetch request
+    const bundleId = process.env.APNS_BUNDLE_ID;
+    if (typeof bundleId !== "string") {
+      throw new Error("APNS_BUNDLE_ID environment variable is not set correctly");
+    }
+
+    const headers = {
+      authorization: `bearer ${this.apnsToken}`,
+      "apns-push-type": "alert",
+      "apns-expiration": "0",
+      "apns-priority": "10",
+      "apns-topic": bundleId,
+    };
+    const response = await fetch(url, {
+      method: "POST",
+      headers,
+      body: JSON.stringify({
+        aps: {
+          alert: {
+            title: "Shuttle is arriving",
+            body: `Shuttle is approaching ${stop.name} in ${Math.ceil(eta.secondsRemaining / 60)} minutes.`
+          }
+        }
+      }),
+    });
+    const json = await response.json();
+
+    if (response.status !== 200) {
+      console.error(`Notification failed for device ${deviceId}:`, json.reason);
+      return false;
+    }
+    return true;
+  }
+
+  public static getAPNsFullUrlToUse(deviceId: string) {
+    // Construct the fetch request
+    const devBaseUrl = "https://api.sandbox.push.apple.com"
+    const prodBaseUrl = "https://api.push.apple.com"
+    const path = "/3/device/" + deviceId;
+
+    let urlToUse = prodBaseUrl + path;
+    if (process.env.NODE_ENV !== "production") {
+      urlToUse = devBaseUrl + path;
+    }
+    return urlToUse;
+  }
+
+  private async etaSubscriberCallback(eta: IEta) {
+    const tuple = new TupleKey(eta.shuttleId, eta.stopId);
+    if (this.deviceIdsToDeliverTo[tuple.toString()] === undefined) {
+      return;
+    }
+
+    const indicesToRemove = new Set();
+    await Promise.all(this.deviceIdsToDeliverTo[tuple.toString()].map(async (deviceId, index) => {
+      const deliveredSuccessfully = await this.sendEtaNotificationImmediatelyIfSecondsRemainingBelowThreshold(deviceId, eta);
+      if (deliveredSuccessfully) {
+        indicesToRemove.add(index);
+      }
+    }));
+
+    this.deviceIdsToDeliverTo[tuple.toString()] = this.deviceIdsToDeliverTo[tuple.toString()].filter((_, index) => !indicesToRemove.has(index));
+  }
+
+  private async sendEtaNotificationImmediatelyIfSecondsRemainingBelowThreshold(deviceId: string, eta: IEta) {
+    if (eta.secondsRemaining > this.secondsThresholdForNotificationToFire) {
+      return false;
+    }
+
+    return await this.sendEtaNotificationImmediately({
+      deviceId,
+      shuttleId: eta.shuttleId,
+      stopId: eta.stopId,
+    });
+  }
+
+  /**
+   * Queue a notification to be sent.
+   * @param deviceId The device ID to send the notification to.
+   * @param shuttleId Shuttle ID of ETA object to check.
+   * @param stopId Stop ID of ETA object to check.
+   */
+  public async scheduleNotification({ deviceId, shuttleId, stopId }: ScheduledNotificationData) {
+    const tuple = new TupleKey(shuttleId, stopId);
+    if (this.deviceIdsToDeliverTo[tuple.toString()] === undefined) {
+      this.deviceIdsToDeliverTo[tuple.toString()] = [deviceId];
+    } else {
+      this.deviceIdsToDeliverTo[tuple.toString()].push(deviceId);
+    }
+
+    this.repository.unsubscribeFromEtaUpdates(this.etaSubscriberCallback);
+    this.repository.subscribeToEtaUpdates(this.etaSubscriberCallback);
+  }
+
+  /**
+   * Cancel a pending notification.
+   * @param deviceId The device ID of the notification.
+   * @param shuttleId Shuttle ID of the ETA object.
+   * @param stopId Stop ID of the ETA object.
+   */
+  public async cancelNotificationIfExists({ deviceId, shuttleId, stopId }: ScheduledNotificationData) {
+    const tupleKey = new TupleKey(shuttleId, stopId);
+    if (
+      this.deviceIdsToDeliverTo[tupleKey.toString()] === undefined
+      || !this.deviceIdsToDeliverTo[tupleKey.toString()].includes(deviceId)
+    ) {
+      return;
+    }
+
+    const index = this.deviceIdsToDeliverTo[tupleKey.toString()].findIndex(id => id === deviceId);
+    if (index !== -1) {
+      this.deviceIdsToDeliverTo[tupleKey.toString()].splice(index, 1);
+    }
+  }
+
+  /**
+   * Check whether the notification is scheduled.
+   * @param deviceId
+   * @param shuttleId
+   * @param stopId
+   */
+  public isNotificationScheduled({ deviceId, shuttleId, stopId }: ScheduledNotificationData): boolean {
+    const tuple = new TupleKey(shuttleId, stopId);
+    if (this.deviceIdsToDeliverTo[tuple.toString()] === undefined) {
+      return false;
+    }
+    return this.deviceIdsToDeliverTo[tuple.toString()].includes(deviceId);
+  }
+}

test/services/NotificationServiceTests.test.ts

@@ -0,0 +1,226 @@
+import { beforeEach, describe, expect, it, jest } from "@jest/globals";
+import { NotificationService } from "../../src/services/NotificationService";
+import { UnoptimizedInMemoryRepository } from "../../src/repositories/UnoptimizedInMemoryRepository";
+import fs from "fs";
+import { IEta, IShuttle, IStop } from "../../src/entities/entities";
+import { resetGlobalFetchMockJson, updateGlobalFetchMockJson } from "../testHelpers/fetchMockHelpers";
+import { addMockShuttleToRepository, addMockStopToRepository } from "../testHelpers/repositorySetupHelpers";
+
+jest.mock("fs");
+
+const sampleKey = `-----BEGIN PRIVATE KEY-----
+MIGTAgEAMBMGByqGSM49AgEGCCqGSM49AwEHBHkwdwIBAQQgsrmSAZIagOfCP8sB
+Wi2CBXG1Oo7v1bispIZCwIr4RDegCgYIKoZIzj0DAQehRANCAATZHxV2wQJLMBq+
+ya+yfGi3g2ZUv6hrfe+j08ytekPHjXS0qzJoVELzKHa6EL9YAoZDXBtB6h+fGhXe
+SOcONbaf
+-----END PRIVATE KEY-----`
+
+/**
+ * Wait for a condition to become true until the timeout
+ * is hit.
+ * @param condition
+ * @param timeoutMilliseconds
+ * @param intervalMilliseconds
+ */
+async function waitForCondition(condition: () => boolean, timeoutMilliseconds = 5000, intervalMilliseconds = 500) {
+  const startTime = Date.now();
+  while (!condition()) {
+    if (Date.now() - startTime > timeoutMilliseconds) {
+      throw new Error("Timeout waiting for condition");
+    }
+    await new Promise((resolve) => setTimeout(resolve, intervalMilliseconds));
+  }
+}
+
+/**
+ * Wait for a specified number of milliseconds.
+ * @param ms
+ */
+async function waitForMilliseconds(ms: number): Promise<void> {
+  await new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+describe("NotificationService", () => {
+  let repository: UnoptimizedInMemoryRepository
+  let notificationService: NotificationService;
+
+  beforeEach(() => {
+    repository = new UnoptimizedInMemoryRepository();
+    notificationService = new NotificationService(repository);
+
+    // Ensure that tests don't hit the server
+    process.env = {
+      ...process.env,
+      APNS_KEY_ID: "1",
+      APNS_TEAM_ID: "1",
+      APNS_KEY_PATH: "./dummy-path.p8",
+      APNS_BUNDLE_ID: "dev.bchen.ProjectInter"
+    };
+
+    (fs.readFileSync as jest.Mock).mockReturnValue(sampleKey);
+
+    resetGlobalFetchMockJson();
+  })
+
+  describe("reloadAPNsTokenIfTimePassed", () => {
+    it("reloads the token if token hasn't been generated yet", async () => {
+      notificationService.reloadAPNsTokenIfTimePassed();
+      expect(notificationService.lastRefreshedTimeMs).toBeDefined();
+    });
+
+    it("doesn't reload the token if last refreshed time is recent", async () => {
+      notificationService.reloadAPNsTokenIfTimePassed();
+      const lastRefreshedTimeMs = notificationService.lastRefreshedTimeMs;
+
+      notificationService.reloadAPNsTokenIfTimePassed();
+      // Expect no change to have occurred
+      expect(lastRefreshedTimeMs).toEqual(notificationService.lastRefreshedTimeMs);
+    });
+  })
+
+  function generateNotificationDataAndEta(shuttle: IShuttle, stop: IStop) {
+    const eta: IEta = {
+      shuttleId: shuttle.id,
+      stopId: stop.id,
+      secondsRemaining: 120,
+    };
+
+    const notificationData1 = {
+      deviceId: "1",
+      shuttleId: eta.shuttleId,
+      stopId: eta.stopId,
+    }
+    const notificationData2 = {
+      ...notificationData1,
+      deviceId: "2",
+    }
+    return { eta, notificationData1, notificationData2 };
+  }
+
+  describe("scheduleNotification", () => {
+    it("schedules the notification", async () => {
+      // arrange
+      const notificationData = {
+        deviceId: "1",
+        shuttleId: "1",
+        stopId: "1"
+      };
+
+      await notificationService.scheduleNotification(notificationData);
+
+      const isNotificationScheduled = notificationService.isNotificationScheduled(notificationData);
+      expect(isNotificationScheduled).toEqual(true);
+    });
+
+    it("sends and clears correct notification after ETA changed", async () => {
+      // Arrange
+      const shuttle = await addMockShuttleToRepository(repository, "1");
+      const stop = await addMockStopToRepository(repository, "1");
+
+      const { eta, notificationData1, notificationData2 } = generateNotificationDataAndEta(shuttle, stop);
+
+      // Simulate 200 + empty object for successful push notification
+      updateGlobalFetchMockJson({});
+
+      // Act
+      await notificationService.scheduleNotification(notificationData1);
+      await notificationService.scheduleNotification(notificationData2);
+      await repository.addOrUpdateEta(eta);
+
+      // Assert
+      // Because repository publisher calls subscriber without await
+      // wait for the change to occur first
+      await waitForCondition(() => !notificationService.isNotificationScheduled(notificationData1));
+
+      expect(fetch as jest.Mock).toHaveBeenCalledTimes(2);
+      const isFirstNotificationScheduled = notificationService.isNotificationScheduled(notificationData1);
+      const isSecondNotificationScheduled = notificationService.isNotificationScheduled(notificationData2);
+      // No longer scheduled after being sent
+      expect(isFirstNotificationScheduled).toBe(false);
+      expect(isSecondNotificationScheduled).toBe(false);
+    });
+
+    it("doesn't send notification if seconds threshold not exceeded", async () => {
+      // Arrange
+      const shuttle = await addMockShuttleToRepository(repository, "1");
+      const stop = await addMockStopToRepository(repository, "1");
+      const { eta, notificationData1 } = generateNotificationDataAndEta(shuttle, stop);
+      eta.secondsRemaining = notificationService.secondsThresholdForNotificationToFire + 100;
+
+      updateGlobalFetchMockJson({});
+
+      // Act
+      await notificationService.scheduleNotification(notificationData1);
+      await repository.addOrUpdateEta(eta);
+
+      // Assert
+      await waitForMilliseconds(500);
+      const isNotificationScheduled = notificationService.isNotificationScheduled(notificationData1);
+      expect(isNotificationScheduled).toBe(true);
+    });
+
+    it("leaves notification in array if delivery unsuccessful", async () => {
+      // Arrange
+      const shuttle = await addMockShuttleToRepository(repository, "1");
+      const stop = await addMockStopToRepository(repository, "1");
+      const { eta, notificationData1 } = generateNotificationDataAndEta(shuttle, stop)
+
+      updateGlobalFetchMockJson({}, 400);
+
+      // Act
+      await notificationService.scheduleNotification(notificationData1);
+      await repository.addOrUpdateEta(eta);
+
+      // Assert
+      // The notification should stay scheduled to be retried once
+      // the ETA updates again
+      await waitForMilliseconds(500);
+      const isNotificationScheduled = notificationService.isNotificationScheduled(notificationData1);
+      expect(isNotificationScheduled).toBe(true);
+    });
+  });
+
+  describe('getAPNsFullUrlToUse', () => {
+    it('should return the production URL when NODE_ENV is set to "production"', () => {
+      process.env.NODE_ENV = 'production';
+      const deviceId = 'testDeviceId';
+      const result = NotificationService.getAPNsFullUrlToUse(deviceId);
+      expect(result).toBe(`https://api.push.apple.com/3/device/${deviceId}`);
+    });
+
+    it('should return the sandbox URL when NODE_ENV is not set to "production"', () => {
+      process.env.NODE_ENV = 'development';
+      const deviceId = 'testDeviceId';
+      const result = NotificationService.getAPNsFullUrlToUse(deviceId);
+      expect(result).toBe(`https://api.sandbox.push.apple.com/3/device/${deviceId}`);
+    });
+
+    it('should append the correct device ID to the URL', () => {
+      process.env.NODE_ENV = 'production';
+      const deviceId = 'device123';
+      const result = NotificationService.getAPNsFullUrlToUse(deviceId);
+      expect(result).toBe(`https://api.push.apple.com/3/device/${deviceId}`);
+    });
+  });
+
+  describe("cancelNotification", () => {
+    it("stops notification from sending to given shuttle/stop ID", async () => {
+      // Arrange
+      const shuttle = await addMockShuttleToRepository(repository, "1");
+      const stop = await addMockStopToRepository(repository, "1");
+      const { eta, notificationData1 } = generateNotificationDataAndEta(shuttle, stop);
+
+      updateGlobalFetchMockJson({});
+
+      await notificationService.scheduleNotification(notificationData1);
+
+      // Act
+      await notificationService.cancelNotificationIfExists(notificationData1);
+      await repository.addOrUpdateEta(eta);
+
+      // Assert
+      await waitForMilliseconds(500);
+      expect(fetch as jest.Mock).toHaveBeenCalledTimes(0);
+    });
+  });
+});