config-overrides.js

/**
 * Override things of the default create-react-app configuration here
 *
 * This is using react-app-rewired by @timarney
 */

const debug = require('debug')('build:config-overrides');
const webpack = require('webpack');
const { injectBabelPlugin } = require('react-app-rewired');
const rewireStyledComponents = require('react-app-rewire-styled-components');
const rewireReactHotLoader = require('react-app-rewire-hot-loader');
const swPrecachePlugin = require('sw-precache-webpack-plugin');
const fs = require('fs');
const path = require('path');
const match = require('micromatch');
const WriteFilePlugin = require('write-file-webpack-plugin');
const { ReactLoadablePlugin } = require('react-loadable/webpack');
const OfflinePlugin = require('offline-plugin');
const { BundleAnalyzerPlugin } = require('webpack-bundle-analyzer');
const BundleBuddyWebpackPlugin = require('bundle-buddy-webpack-plugin');
const CircularDependencyPlugin = require('circular-dependency-plugin');

// Recursively walk a folder and get all file paths
function walkFolder(currentDirPath, callback) {
  fs.readdirSync(currentDirPath).forEach(name => {
    // Skip dot files
    if (name.indexOf('.') === 0) return;

    var filePath = path.join(currentDirPath, name);
    var stat = fs.statSync(filePath);

    if (stat.isFile()) {
      callback(filePath, stat);
    } else if (stat.isDirectory()) {
      walkFolder(filePath, callback);
    }
  });
}

const isServiceWorkerPlugin = plugin => plugin instanceof swPrecachePlugin;

const removeEslint = config => {
  config.module.rules = config.module.rules.filter(rule => {
    // Filter the eslint loader based on its options
    if (rule.use) {
      return rule.use.every(use => {
        if (!use.options) return true;
        return !use.options.eslintPath;
      });
    }
    return true;
  });
};

// Make sure webpack transpiles files in the shared folder
const transpileShared = config => {
  config.module.rules.forEach(rule => {
    if (!rule.oneOf) return;

    rule.oneOf.forEach(loader => {
      if (!loader.include) return;
      if (!loader.options) return;
      // The loader config we're looking for is for JS files,
      // so we look whether the config has a babelrc option
      if (!Object.keys(loader.options).includes('babelrc')) return;

      // Add the shared folder to the locations
      // that should be transpiled
      loader.include = [loader.include, path.resolve(__dirname, './shared')];
    });
  });

  return config;
};

module.exports = function override(config, env) {
  if (process.env.REACT_APP_MAINTENANCE_MODE === 'enabled') {
    console.error('\n\n⚠️ ----MAINTENANCE MODE ENABLED----⚠️\n\n');
  }
  if (process.env.NODE_ENV === 'development') {
    config.output.path = path.join(__dirname, './build');
    config = rewireReactHotLoader(config, env);
    config.plugins.push(
      WriteFilePlugin({
        log: true,
        useHashIndex: false,
      })
    );
  }
  config.plugins.push(
    new ReactLoadablePlugin({
      filename: './build/react-loadable.json',
    })
  );
  config = injectBabelPlugin('react-loadable/babel', config);
  config = transpileShared(config);
  // Filter the default serviceworker plugin, add offline plugin instead
  config.plugins = config.plugins.filter(
    plugin => !isServiceWorkerPlugin(plugin)
  );
  // Get all public files so they're cached by the SW
  let externals = [];
  walkFolder('./public/', file => {
    if (file.indexOf('index.html') > -1) return;
    externals.push(file.replace(/public/, ''));
  });
  config.plugins.push(
    new OfflinePlugin({
      // We don't want to cache anything
      caches: {},
      externals,
      autoUpdate: true,
      // NOTE(@mxstbr): Normally this is handled by setting
      // appShell: './index.html'
      // but we don't want to serve the app shell for the `/api` and `/auth` routes
      // which means we have to manually do this and filter any of those routes out
      cacheMaps: [
        {
          match: function() {
            return false;
          },
          requestTypes: ['navigate'],
        },
      ],
      rewrites: arg => arg,
      ServiceWorker: {
        entry: './public/push-sw.js',
        events: true,
        prefetchRequest: {
          mode: 'cors',
          credentials: 'include',
        },
      },
      AppCache: false,
    })
  );
  if (process.env.ANALYZE_BUNDLE === 'true') {
    debug('Bundle analyzer enabled');
    config.plugins.push(
      new BundleAnalyzerPlugin({
        analyzerMode: 'static',
        openAnalyzer: false,
      })
    );
  }
  if (process.env.BUNDLE_BUDDY === 'true') {
    config.plugins.push(new BundleBuddyWebpackPlugin());
  }
  config.plugins.unshift(
    new webpack.optimize.CommonsChunkPlugin({
      names: ['bootstrap'],
      filename: 'static/js/[name].[hash].js',
      minChunks: Infinity,
    })
  );
  if (process.env.NODE_ENV === 'production') {
    removeEslint(config);
    config.plugins.push(new webpack.optimize.ModuleConcatenationPlugin());
    config.plugins.push(
      new webpack.DefinePlugin({
        'process.env': {
          SENTRY_DSN_CLIENT: `"${process.env.SENTRY_DSN_CLIENT}"`,
        },
      })
    );
  }

  // NOTE(@mxstbr): This works around an issue where webpack was resolving the "module" path of b2a
  // which breaks when imported on the fronted. We need to import the built version.
  config.resolve.alias.b2a = path.resolve(
    __dirname,
    'node_modules/b2a/lib/index.js'
  );
  config.plugins.push(
    new CircularDependencyPlugin({
      cwd: process.cwd(),
      failOnError: true,
    })
  );
  return rewireStyledComponents(config, env, { ssr: true });
};