add deleteNotificationById function

packages/notification-services-controller/src/NotificationServicesController/NotificationServicesController.test.ts

@@ -590,6 +590,24 @@ describe('metamask-notifications - getNotificationsByType', () => {
   });
 });
 
+describe('metamask-notifications - deleteNotificationById', () => {
+  it('will delete a notification by its id', async () => {
+    const { messenger } = mockNotificationMessenger();
+    const processedSnapNotification = processSnapNotification(
+      createMockSnapNotification(),
+    );
+    const controller = new NotificationServicesController({
+      messenger,
+      env: { featureAnnouncements: featureAnnouncementsEnv },
+      state: { metamaskNotificationsList: [processedSnapNotification] },
+    });
+
+    await controller.deleteNotificationById(processedSnapNotification.id);
+
+    expect(controller.state.metamaskNotificationsList).toHaveLength(0);
+  });
+});
+
 describe('metamask-notifications - markMetamaskNotificationsAsRead()', () => {
   const arrangeMocks = (options?: { onChainMarkAsReadFails: boolean }) => {
     const messengerMocks = mockNotificationMessenger();

packages/notification-services-controller/src/NotificationServicesController/NotificationServicesController.ts

@@ -201,13 +201,19 @@ export type NotificationServicesControllerGetNotificationsByType = {
   handler: NotificationServicesController['getNotificationsByType'];
 };
 
+export type NotificationServicesControllerDeleteNotificationById = {
+  type: `${typeof controllerName}:deleteNotificationById`;
+  handler: NotificationServicesController['deleteNotificationById'];
+};
+
 // Messenger Actions
 export type Actions =
   | NotificationServicesControllerGetStateAction
   | NotificationServicesControllerUpdateMetamaskNotificationsList
   | NotificationServicesControllerDisableNotificationServices
   | NotificationServicesControllerSelectIsNotificationServicesEnabled
-  | NotificationServicesControllerGetNotificationsByType;
+  | NotificationServicesControllerGetNotificationsByType
+  | NotificationServicesControllerDeleteNotificationById;
 
 // Allowed Actions
 export type AllowedActions =
@@ -584,6 +590,11 @@ export default class NotificationServicesController extends BaseController<
       `${controllerName}:getNotificationsByType`,
       this.getNotificationsByType.bind(this),
     );
+
+    this.messagingSystem.registerActionHandler(
+      `${controllerName}:deleteNotificationById`,
+      this.deleteNotificationById.bind(this),
+    );
   }
 
   #clearLoadingStates(): void {
@@ -1165,6 +1176,33 @@ export default class NotificationServicesController extends BaseController<
     );
   }
 
+  /**
+   * Used to delete a notification by id.
+   *
+   * Note: This function should only be used for notifications that are stored
+   * in this controller directly, currently only snaps notifications.
+   *
+   * @param id - The id of the notification to delete.
+   */
+  public async deleteNotificationById(id: string) {
+    const fetchedNotification = this.state.metamaskNotificationsList.find(
+      (notification) => notification.id === id,
+    );
+
+    assert(
+      fetchedNotification,
+      'The notification to be deleted does not exist.',
+    );
+
+    const newList = this.state.metamaskNotificationsList.filter(
+      (notification) => notification.id !== id,
+    );
+
+    this.update((state) => {
+      state.metamaskNotificationsList = newList;
+    });
+  }
+
   /**
    * Marks specified metamask notifications as read.
    *