next.config.js

const withOffline = require("next-offline");
const withSourceMaps = require("@zeit/next-source-maps")();

const env = {
  FIREBASE_API_KEY: process.env.FIREBASE_API_KEY,
  FIREBASE_AUTH_DOMAIN: process.env.FIREBASE_AUTH_DOMAIN,
  FIREBASE_DATABASE_URL: process.env.FIREBASE_DATABASE_URL,
  FIREBASE_PROJECT_ID: process.env.FIREBASE_PROJECT_ID,
  FIREBASE_STORAGE_BUCKET: process.env.FIREBASE_STORAGE_BUCKET,
  FIREBASE_MESSAGING_SENDER_ID: process.env.FIREBASE_MESSAGING_SENDER_ID,
  FIREBASE_APP_ID: process.env.FIREBASE_APP_ID,
  FIREBASE_MEASUREMENT_ID: process.env.FIREBASE_MEASUREMENT_ID,
  GA_ID: process.env.GA_ID,
  SENTRY_DSN: process.env.SENTRY_DSN,
};

const nextConfig = {
  env,
  i18n: {
    locales: ["en", "fr", "es", "ru", "ptbr", "de"],
    defaultLocale: "en",
  },
  target: "serverless",
  transformManifest: (manifest) => ["/"].concat(manifest), // add the homepage to the cache
  // Trying to set NODE_ENV=production when running yarn dev causes a build-time error so we
  // turn on the SW in dev mode so that we can actually test it
  generateInDevMode: true,
  workboxOpts: {
    swDest: "static/service-worker.js",
    runtimeCaching: [
      {
        urlPattern: /^https?.*/,
        handler: "NetworkFirst",
        options: {
          cacheName: "https-calls",
          networkTimeoutSeconds: 15,
          expiration: {
            maxEntries: 150,
            maxAgeSeconds: 30 * 24 * 60 * 60, // 1 month
          },
          cacheableResponse: {
            statuses: [0, 200],
          },
        },
      },
    ],
  },
};

module.exports = withSourceMaps(withOffline(nextConfig));