add tests and implementation for notification deletes

src/repositories/InMemoryNotificationRepository.ts

@@ -19,7 +19,7 @@ export class InMemoryNotificationRepository implements NotificationRepository {
    */
   private deviceIdsToDeliverTo: { [key: string]: DeviceIdSecondsThresholdAssociation } = {}
 
-  private subscribers: Listener[] = [];
+  private listeners: Listener[] = [];
 
   async getAllNotificationsForShuttleAndStopId(shuttleId: string, stopId: string) {
     const tuple = new TupleKey(shuttleId, stopId);
@@ -81,12 +81,34 @@ export class InMemoryNotificationRepository implements NotificationRepository {
       return;
     }
 
+    const secondsThreshold = this.deviceIdsToDeliverTo[tupleKey.toString()][deviceId];
     delete this.deviceIdsToDeliverTo[tupleKey.toString()][deviceId];
+    this.listeners.forEach((listener) => {
+      const event: NotificationEvent = {
+        event: 'delete',
+        notification: {
+          deviceId,
+          shuttleId,
+          stopId,
+          secondsThreshold
+        }
+      }
+
+      listener(event);
+    })
   }
 
   public subscribeToNotificationChanges(listener: Listener): void {
+    const index = this.listeners.findIndex((existingListener) => existingListener == listener);
+    if (index < 0) {
+      this.listeners.push(listener);
+    }
   }
 
   public unsubscribeFromNotificationChanges(listener: Listener): void {
+    const index = this.listeners.findIndex((existingListener) => existingListener == listener);
+    if (index >= 0) {
+      this.listeners.splice(index, 1);
+    }
   }
 }

test/repositories/InMemoryNotificationRepositoryTests.test.ts

@@ -1,5 +1,6 @@
-import { beforeEach, describe, expect, it } from "@jest/globals";
+import { beforeEach, describe, expect, it, jest } from "@jest/globals";
 import { InMemoryNotificationRepository } from "../../src/repositories/InMemoryNotificationRepository";
+import { NotificationEvent } from "../../src/repositories/NotificationRepository";
 
 describe("InMemoryNotificationRepository", () => {
   let repo: InMemoryNotificationRepository;
@@ -71,16 +72,13 @@ describe("InMemoryNotificationRepository", () => {
   describe("deleteNotificationIfExists", () => {
     it("deletes the notification", async () => {
       await repo.addOrUpdateNotification(notification);
-      await repo.deleteNotificationIfExists({
-        deviceId: "device1",
-        shuttleId: "shuttle1",
-        stopId: "stop1"
-      });
+      await repo.deleteNotificationIfExists(notification);
 
       const result = await repo.getAllNotificationsForShuttleAndStopId("shuttle1", "stop1");
       expect(result).toHaveLength(0);
     });
 
+
     it("does nothing if there's no notification", async () => {
       await expect(repo.deleteNotificationIfExists({
         deviceId: "device1",
@@ -89,4 +87,29 @@ describe("InMemoryNotificationRepository", () => {
       })).resolves.not.toThrow();
     });
   });
+
+  describe("subscribeToNotificationChanges", () => {
+    it("calls subscribers when something is added", async () => {
+
+    });
+
+    it("calls subscribers when something is deleted", async () => {
+      await repo.addOrUpdateNotification(notification);
+
+      const mockCallback = jest.fn();
+      repo.subscribeToNotificationChanges(mockCallback);
+
+      await repo.deleteNotificationIfExists(notification);
+
+      expect(mockCallback).toHaveBeenCalledTimes(1);
+
+      const expectedEvent: NotificationEvent = {
+        event: 'delete',
+        notification: {
+          ...notification,
+        },
+      };
+      expect(mockCallback).toHaveBeenCalledWith(expectedEvent);
+    });
+  })
 });