next.config.js

// Use the hidden-source-map option when you don't want the source maps to be
// publicly available on the servers, only to the error reporting
const withSourceMaps = require("@zeit/next-source-maps");

// Use the SentryWebpack plugin to upload the source maps during build step
const SentryWebpackPlugin = require("@sentry/webpack-plugin");

const isProd = process.env.NODE_ENV === "production";

module.exports = withSourceMaps({
  webpack: (config, options) => {
    // In `pages/_app.js`, Sentry is imported from @sentry/node. While
    // @sentry/browser will run in a Node.js environment, @sentry/node will use
    // Node.js-only APIs to catch even more unhandled exceptions.
    //
    // This works well when Next.js is SSRing your page on a server with
    // Node.js, but it is not what we want when your client-side bundle is being
    // executed by a browser.
    //
    // Luckily, Next.js will call this webpack function twice, once for the
    // server and once for the client. Read more:
    // https://nextjs.org/docs#customizing-webpack-config
    //
    // So ask Webpack to replace @sentry/node imports with @sentry/browser when
    // building the browser's bundle
    if (!options.isServer) {
      config.resolve.alias["@sentry/node"] = "@sentry/browser";
      config.node = {
        fs: "empty",
      };

      require("./lib/generate-sitemap.ts");
    }

    // When all the Sentry configuration env variables are available/configured
    // The Sentry webpack plugin gets pushed to the webpack plugins to build
    // and upload the source maps to sentry.
    // This is an alternative to manually uploading the source maps
    // Note: This is disabled in development mode.
    if (
      process.env.SENTRY_DSN &&
      process.env.SENTRY_ORG &&
      process.env.SENTRY_PROJECT &&
      process.env.SENTRY_AUTH_TOKEN &&
      isProd
    ) {
      config.plugins.push(
        new SentryWebpackPlugin({
          include: ".next",
          ignore: ["node_modules"],
          urlPrefix: "~/_next",
          release: options.buildId,
        })
      );
    }

    // Generate sitemap.xml on the server. This will be generated in domain.com/sitemap.xml
    if (options.isServer) {
      require("./lib/generate-sitemap.ts");
    }

    return config;
  },
});