How to handle redirects in Next.js?

// next.config.js
module.exports = {
  async redirects() {
    return [
      {
        source: '/old-page',
        destination: '/new-page',
        permanent: true, // 308 status
      },
      {
        source: '/blog/:slug',
        destination: '/posts/:slug',
        permanent: false, // 307 status
      },
      {
        // Regex support
        source: '/docs/:path((?!api).*)',
        destination: '/documentation/:path',
        permanent: true,
      },
    ];
  },
};

// In Server Component
import { redirect } from 'next/navigation';

async function checkAuth() {
  const user = await getUser();
  if (!user) {
    redirect('/login');
  }
}

// In Route Handler
import { redirect } from 'next/navigation';

export async function GET() {
  redirect('/dashboard');
}

'use client';

import { useRouter } from 'next/navigation';

export default function LoginButton() {
  const router = useRouter();

  const handleLogin = async () => {
    await login();
    router.push('/dashboard');
    // or router.replace('/dashboard');
  };
}