Add notification banner component

docs/upgrade-to-6.0.md

@@ -31,6 +31,17 @@ The [panel](https://service-manual.nhs.uk/design-system/components/panel) compon
 
 This replaces the [list panel component](#list-panel) which was removed in NHS.UK frontend v6.0.0.
 
+### Notification banner component
+
+The [notification banner](https://service-manual.nhs.uk/design-system/components/notification-banner) component from NHS.UK frontend v10 has been added:
+
+```jsx
+<NotificationBanner>
+  <NotificationBanner.Heading>Upcoming maintenance</NotificationBanner.Heading>
+  <p>The service will be unavailable from 8pm to 9pm on Thursday 1 January 2025.</p>
+</NotificationBanner>
+```
+
 ### Support for React Server Components (RSC)
 
 All components have been tested as React Server Components (RSC) but due to [multipart namespace component limitations](https://ivicabatinic.from.hr/posts/multipart-namespace-components-addressing-rsc-and-dot-notation-issues) an alternative syntax (without dot notation) can be used as a workaround:
@@ -440,8 +451,9 @@ You must rename the `Select` prop `selectRef` to `ref` for consistency with othe
 To align with NHS.UK frontend, the skip link component focuses the main content rather than the first heading on the page:
 
 ```html
-<main class="nhsuk-main-wrapper id="maincontent">
+<main class="nhsuk-main-wrapper" id="maincontent">
   <!-- // ... -->
+</main>
 ```
 
 For accessibility reasons, you must make the following changes:

src/__tests__/index.test.ts

@@ -91,6 +91,10 @@ describe('Index', () => {
       'NavAZ',
       'NavAZDisabledItem',
       'NavAZLinkItem',
+      'NotificationBanner',
+      'NotificationBannerHeading',
+      'NotificationBannerLink',
+      'NotificationBannerTitle',
       'Pagination',
       'PaginationLink',
       'Panel',

src/components/content-presentation/index.ts

@@ -4,6 +4,7 @@ export * from './hero/index.js';
 export * from './icons/index.js';
 export * from './images/index.js';
 export * from './inset-text/index.js';
+export * from './notification-banner/index.js';
 export * from './panel/index.js';
 export * from './summary-list/index.js';
 export * from './table/index.js';

src/components/content-presentation/notification-banner/NotificationBanner.tsx

@@ -0,0 +1,95 @@
+'use client';
+
+import {
+  Children,
+  createRef,
+  forwardRef,
+  useEffect,
+  useState,
+  type ComponentPropsWithoutRef,
+} from 'react';
+import classNames from 'classnames';
+import {
+  NotificationBannerHeading,
+  NotificationBannerLink,
+  NotificationBannerTitle,
+} from './components/index.js';
+import { type NotificationBanner as NotificationBannerModule } from 'nhsuk-frontend';
+import { childIsOfComponentType } from '#util/types/TypeGuards.js';
+
+export interface NotificationBannerProps extends ComponentPropsWithoutRef<'div'> {
+  success?: boolean;
+  disableAutoFocus?: boolean;
+  titleId?: string;
+}
+
+const NotificationBannerComponent = forwardRef<HTMLDivElement, NotificationBannerProps>(
+  (props, forwardedRef) => {
+    const { children, className, title, titleId, success, role, disableAutoFocus, ...rest } = props;
+
+    const [moduleRef] = useState(() => forwardedRef || createRef<HTMLDivElement>());
+    const [instanceError, setInstanceError] = useState<Error>();
+    const [instance, setInstance] = useState<NotificationBannerModule>();
+
+    useEffect(() => {
+      if (!('current' in moduleRef) || !moduleRef.current || instance) {
+        return;
+      }
+
+      import('nhsuk-frontend')
+        .then(({ NotificationBanner }) => setInstance(new NotificationBanner(moduleRef.current)))
+        .catch(setInstanceError);
+    }, [moduleRef, instance]);
+
+    const items = Children.toArray(children);
+
+    const titleElement = items.find((child) =>
+      childIsOfComponentType(child, NotificationBannerTitle, {
+        className: 'nhsuk-notification-banner__title',
+      }),
+    );
+
+    const titleElementId = titleElement?.props.id || titleId || 'nhsuk-notification-banner-title';
+
+    const contentItems = items.filter((child) => child !== titleElement);
+
+    if (instanceError) {
+      throw instanceError;
+    }
+
+    return (
+      <div
+        className={classNames(
+          'nhsuk-notification-banner',
+          { 'nhsuk-notification-banner--success': success },
+          className,
+        )}
+        aria-labelledby={titleElementId}
+        data-module="nhsuk-notification-banner"
+        data-disable-auto-focus={disableAutoFocus}
+        ref={moduleRef}
+        role={role || (success ? 'alert' : 'region')}
+        {...rest}
+      >
+        <div className="nhsuk-notification-banner__header">
+          {titleElement ? (
+            <>{titleElement}</>
+          ) : (
+            <NotificationBannerTitle id={titleElementId} success={success}>
+              {title}
+            </NotificationBannerTitle>
+          )}
+        </div>
+        <div className="nhsuk-notification-banner__content">{contentItems}</div>
+      </div>
+    );
+  },
+);
+
+NotificationBannerComponent.displayName = 'NotificationBanner';
+
+export const NotificationBanner = Object.assign(NotificationBannerComponent, {
+  Title: NotificationBannerTitle,
+  Heading: NotificationBannerHeading,
+  Link: NotificationBannerLink,
+});