[PM-19806] Add Special Foreground Notifications Service (#14094)

* Add Special Foreground Notifications Service

* Add link to method

apps/browser/src/platform/notifications/foreground-notifications.service.ts

@@ -0,0 +1,31 @@
+import { Observable, Subscription } from "rxjs";
+
+import { NotificationResponse } from "@bitwarden/common/models/response/notification.response";
+import { LogService } from "@bitwarden/common/platform/abstractions/log.service";
+import { NotificationsService } from "@bitwarden/common/platform/notifications";
+import { UserId } from "@bitwarden/common/types/guid";
+
+// Eventually if we want to support listening to notifications from browser foreground we
+// will only ever create a single SignalR connection, likely messaging to the background to reuse its connection.
+export class ForegroundNotificationsService implements NotificationsService {
+  notifications$: Observable<readonly [NotificationResponse, UserId]>;
+
+  constructor(private readonly logService: LogService) {
+    this.notifications$ = new Observable((subscriber) => {
+      this.logService.warning(
+        "Notifications will never emit from browser foreground, you will need to listen to messages from `DefaultNotificationsService.processNotification`",
+      );
+      subscriber.complete();
+    });
+  }
+
+  startListening(): Subscription {
+    throw new Error("startListening should never be called from browser foreground.");
+  }
+  reconnectFromActivity(): void {
+    throw new Error("Activity should not be managed from browser foreground.");
+  }
+  disconnectFromInactivity(): void {
+    throw new Error("Activity should not be managed from browser foreground.");
+  }
+}

apps/browser/src/popup/services/services.module.ts

@@ -94,6 +94,7 @@ import { Message, MessageListener, MessageSender } from "@bitwarden/common/platf
 // eslint-disable-next-line no-restricted-imports -- Used for dependency injection
 import { SubjectMessageSender } from "@bitwarden/common/platform/messaging/internal";
 import { flagEnabled } from "@bitwarden/common/platform/misc/flags";
+import { NotificationsService } from "@bitwarden/common/platform/notifications";
 import { TaskSchedulerService } from "@bitwarden/common/platform/scheduling";
 import { ConsoleLogService } from "@bitwarden/common/platform/services/console-log.service";
 import { ContainerService } from "@bitwarden/common/platform/services/container.service";
@@ -157,6 +158,7 @@ import { runInsideAngular } from "../../platform/browser/run-inside-angular.oper
 import { ZonedMessageListenerService } from "../../platform/browser/zoned-message-listener.service";
 import { ChromeMessageSender } from "../../platform/messaging/chrome-message.sender";
 /* eslint-enable no-restricted-imports */
+import { ForegroundNotificationsService } from "../../platform/notifications/foreground-notifications.service";
 import { OffscreenDocumentService } from "../../platform/offscreen-document/abstractions/offscreen-document";
 import { DefaultOffscreenDocumentService } from "../../platform/offscreen-document/offscreen-document.service";
 import { PopupCompactModeService } from "../../platform/popup/layout/popup-compact-mode.service";
@@ -660,6 +662,11 @@ const safeProviders: SafeProvider[] = [
     useClass: DefaultSshImportPromptService,
     deps: [DialogService, ToastService, PlatformUtilsService, I18nServiceAbstraction],
   }),
+  safeProvider({
+    provide: NotificationsService,
+    useClass: ForegroundNotificationsService,
+    deps: [LogService],
+  }),
 ];
 
 @NgModule({

libs/common/src/platform/notifications/internal/default-notifications.service.ts

@@ -7,6 +7,7 @@ import {
   map,
   mergeMap,
   Observable,
+  share,
   switchMap,
 } from "rxjs";
 
@@ -66,6 +67,7 @@ export class DefaultNotificationsService implements NotificationsServiceAbstract
           map((notification) => [notification, activeAccountId] as const),
         );
       }),
+      share(), // Multiple subscribers should only create a single connection to the server
     );
   }
 

libs/common/src/platform/notifications/notifications.service.ts

@@ -3,10 +3,18 @@ import { Observable, Subscription } from "rxjs";
 import { NotificationResponse } from "@bitwarden/common/models/response/notification.response";
 import { UserId } from "@bitwarden/common/types/guid";
 
+// eslint-disable-next-line @typescript-eslint/no-unused-vars -- Needed to link to API
+import type { DefaultNotificationsService } from "./internal";
+
 /**
  * A service offering abilities to interact with push notifications from the server.
  */
 export abstract class NotificationsService {
+  /**
+   * @deprecated This method should not be consumed, an observable to listen to server
+   * notifications will be available one day but it is not ready to be consumed generally.
+   * Please add code reacting to notifications in {@link DefaultNotificationsService.processNotification}
+   */
   abstract notifications$: Observable<readonly [NotificationResponse, UserId]>;
   /**
    * Starts automatic listening and processing of notifications, should only be called once per application,