Next.js: Handle 404s

Uset the notFound() helper function within a route to display the not-found.tsx file:

import { getPostBySlug } from '@/lib/posts'
 
export default async function Page({ params }: { params: { slug: string } }) {
  const { slug } = await params
  const post = getPostBySlug(slug)
 
  if (!post) {
    notFound()
  }
 
  return <div>{post.title}</div>
}