fix: trigger leave when hovered notifications unmount

src/Notification.tsx

@@ -65,7 +65,7 @@ export interface NotificationProps {
   // Function
   onClick?: React.MouseEventHandler<HTMLDivElement>;
   onMouseEnter?: React.MouseEventHandler<HTMLDivElement>;
-  onMouseLeave?: React.MouseEventHandler<HTMLDivElement>;
+  onMouseLeave?: (event?: React.MouseEvent<HTMLDivElement>) => void;
   /** @deprecated Please use `closable.onClose` instead. */
   onClose?: () => void;
 }
@@ -144,7 +144,7 @@ const Notification = React.forwardRef<HTMLDivElement, NotificationProps>((props,
     onMouseEnter?.(event);
   }
 
-  function onInternalMouseLeave(event: React.MouseEvent<HTMLDivElement>) {
+  function onInternalMouseLeave(event?: React.MouseEvent<HTMLDivElement>) {
     setHovering(false);
     if (pauseOnHover && !forcedHovering) {
       onResume();
@@ -158,6 +158,14 @@ const Notification = React.forwardRef<HTMLDivElement, NotificationProps>((props,
     onInternalClose();
   }
 
+  const destroy = useEvent(() => {
+    if (hovering) {
+      onInternalMouseLeave();
+    }
+  });
+
+  React.useEffect(() => destroy, [destroy]);
+
   // ======================== Position ========================
   const offsetRef = React.useRef(offset);
   if (offset !== undefined) {

tests/notification-unmount.test.tsx

@@ -0,0 +1,31 @@
+import { fireEvent, render } from '@testing-library/react';
+import React from 'react';
+import { Notification } from '../src';
+
+describe('Notification unmount', () => {
+  it.each(['hovered', 'never hovered', 'already left'])(
+    'only calls leave when still hovered: %s',
+    (state) => {
+      const onMouseLeave = vi.fn();
+      const { container, unmount } = render(
+        <Notification prefixCls="rc-notification" duration={0} onMouseLeave={onMouseLeave} />,
+      );
+      const notice = container.firstElementChild!;
+
+      if (state !== 'never hovered') {
+        fireEvent.mouseEnter(notice);
+      }
+      if (state === 'already left') {
+        fireEvent.mouseLeave(notice);
+        expect(onMouseLeave).toHaveBeenCalledTimes(1);
+        onMouseLeave.mockClear();
+      }
+
+      unmount();
+      expect(onMouseLeave).toHaveBeenCalledTimes(state === 'hovered' ? 1 : 0);
+      if (state === 'hovered') {
+        expect(onMouseLeave).toHaveBeenCalledWith(undefined);
+      }
+    },
+  );
+});