next.config.mjs

// noinspection JSFileReferences

export default async (_phase, { defaultConfig: _ }) => {
  /**
   * @type {import('next').NextConfig}
   **/
  const config = {
    reactStrictMode: true,
    productionBrowserSourceMaps: true,
    swcMinify: true,
    experimental: {
      esmExternals: true,
      workerThreads: true,
      isrFlushToDisk: false,
      scrollRestoration: true,
      optimizeCss: true
    },
    // compiler: {
    // removeConsole
    // },
    transpilePackages: ['figlet'],
    eslint: {
      dirs: ['pages', 'components', 'lib', 'utilities', 'layouts'] // Only run ESLint on these directories during production builds (next build)
    },
    images: {
      domains: ['cdn2.thecatapi.com', 'i.scdn.co']
    },
    async redirects() {
      return [
        {
          source: '/about',
          destination: '/story',
          permanent: true
        }
      ]
    },
    async headers() {
      return [
        {
          source: '/(.*)',
          headers: securityHeaders
        }
      ]
    }
  }

  // https://securityheaders.com
  const ContentSecurityPolicy = `
  default-src 'self';
  script-src 'self' 'unsafe-eval' 'unsafe-inline';
  style-src 'self' 'unsafe-inline';
  img-src * blob: data:;
  media-src https://p.scdn.co/;
  connect-src *;
  font-src 'self';
`

  const securityHeaders = [
    // https://developer.mozilla.org/en-US/docs/Web/HTTP/CSP
    {
      key: 'Content-Security-Policy',
      value: ContentSecurityPolicy.replace(/\n/g, '')
    },
    // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Referrer-Policy
    {
      key: 'Referrer-Policy',
      value: 'origin-when-cross-origin'
    },
    // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Frame-Options
    {
      key: 'X-Frame-Options',
      value: 'DENY'
    },
    // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Content-Type-Options
    {
      key: 'X-Content-Type-Options',
      value: 'nosniff'
    },
    // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-DNS-Prefetch-Control
    {
      key: 'X-DNS-Prefetch-Control',
      value: 'on'
    },
    // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Strict-Transport-Security
    {
      key: 'Strict-Transport-Security',
      value: 'max-age=31536000; includeSubDomains; preload'
    },
    // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Feature-Policy
    // Opt-out of Google FLoC: https://amifloced.org/
    {
      key: 'Permissions-Policy',
      value: 'camera=(), microphone=(), geolocation=(), interest-cohort=()'
    }
  ]

  return config
}