fix: preserve zero notification offset

Author: zombieJ

src/Notification.tsx

@@ -152,7 +152,7 @@ const Notification = React.forwardRef<HTMLDivElement, NotificationProps>((props,
 
   // ======================== Position ========================
   const offsetRef = React.useRef(offset);
-  if (offset) {
+  if (offset !== undefined) {
     offsetRef.current = offset;
   }
 
@@ -209,7 +209,7 @@ const Notification = React.forwardRef<HTMLDivElement, NotificationProps>((props,
     ...style,
   };
 
-  if (mergedOffset) {
+  if (mergedOffset !== undefined) {
     mergedStyle['--notification-y'] = `${mergedOffset}px`;
   }
 

tests/index.test.tsx

@@ -2,7 +2,7 @@ import { fireEvent, render } from '@testing-library/react';
 import React from 'react';
 import { act } from 'react-dom/test-utils';
 import type { NotificationAPI, NotificationConfig, NotificationProgressProps } from '../src';
-import { useNotification } from '../src';
+import { Notification, useNotification } from '../src';
 
 require('../assets/index.less');
 
@@ -618,6 +618,22 @@ describe('Notification.Basic', () => {
     expect(document.querySelector('.rc-notification-notice')).toHaveClass('bamboo');
   });
 
+  it('should support zero offset', () => {
+    const { container, rerender } = render(
+      <Notification prefixCls="rc-notification" description="little" offset={10} />,
+    );
+
+    expect(container.querySelector('.rc-notification-notice')).toHaveStyle({
+      '--notification-y': '10px',
+    });
+
+    rerender(<Notification prefixCls="rc-notification" description="little" offset={0} />);
+
+    expect(container.querySelector('.rc-notification-notice')).toHaveStyle({
+      '--notification-y': '0px',
+    });
+  });
+
   it('should not render section for single content node', () => {
     const { instance } = renderDemo();