feat(ToastNotification): Add onDismiss callback to ToastNotificationProvider (#1236)

- Added `onDismiss` callback as an optional prop to ToastNotificationProvider
- (driveby fix) Added `notifications` as a prop to `onDismiss` callback in `handleGroupedDismiss`
  - Previously, dismissing all notifications would only remove them from context, and the notifications were not provided to the `onDismiss` callback, so nothing would happen.

Author: ndv99

src/components/Notifications/ToastNotification/ToastNotification.test.tsx

@@ -170,4 +170,21 @@ describe("ToastNotification", () => {
     expect(screen.queryByText("Success")).not.toBeInTheDocument();
     expect(screen.queryByText("Failure")).not.toBeInTheDocument();
   });
+
+  it("calls onDismiss for an unfiltered list of notifications", async () => {
+    const onDismiss = jest.fn();
+
+    render(
+      <ToastNotificationList
+        notifications={notifications}
+        onDismiss={onDismiss}
+        groupedCount={groupedCount}
+        show={true}
+      />,
+    );
+
+    await userEvent.click(screen.getByRole("button", { name: "Dismiss all" }));
+
+    expect(onDismiss).toHaveBeenCalledWith(notifications);
+  });
 });

src/components/Notifications/ToastNotification/ToastNotificationList.tsx

@@ -106,7 +106,7 @@ const ToastNotificationList: FC<Props> = ({
       return;
     }
 
-    onDismiss();
+    onDismiss(notifications);
   };
 
   const getSeverityFilters = () => {

src/components/Notifications/ToastNotification/ToastNotificationProvider.tsx

@@ -18,6 +18,10 @@ export type ToastNotificationType = NotificationType & {
   id: string;
 };
 
+interface Props {
+  onDismiss?: (notifications?: ToastNotificationType[]) => void;
+}
+
 interface ToastNotificationHelper {
   notifications: ToastNotificationType[];
   success: (
@@ -148,7 +152,10 @@ console.log(count.positive);
 Alternatively, you can use the `ToastNotification` and `ToastNotificationList` components directly, without using the provider.
 */
 
-const ToastNotificationProvider: FC<PropsWithChildren> = ({ children }) => {
+const ToastNotificationProvider: FC<PropsWithChildren<Props>> = ({
+  children,
+  onDismiss,
+}) => {
   const [notifications, setNotifications] = useState<ToastNotificationType[]>(
     [],
   );
@@ -210,6 +217,10 @@ const ToastNotificationProvider: FC<PropsWithChildren> = ({ children }) => {
   };
 
   const clear = (notifications?: ToastNotificationType[]) => {
+    if (onDismiss) {
+      onDismiss(notifications);
+    }
+
     if (!notifications) {
       setNotifications([]);
       setShowList(false);