#1 Workaround for build issue with MDC adn react-scripts.

config/env.js

@@ -0,0 +1,98 @@
+// @remove-on-eject-begin
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+// @remove-on-eject-end
+'use strict';
+
+const fs = require('fs');
+const path = require('path');
+const paths = require('./paths');
+
+// Make sure that including paths.js after env.js will read .env variables.
+delete require.cache[require.resolve('./paths')];
+
+const NODE_ENV = process.env.NODE_ENV;
+if (!NODE_ENV) {
+  throw new Error(
+    'The NODE_ENV environment variable is required but was not specified.'
+  );
+}
+
+// https://github.com/bkeepers/dotenv#what-other-env-files-can-i-use
+var dotenvFiles = [
+  `${paths.dotenv}.${NODE_ENV}.local`,
+  `${paths.dotenv}.${NODE_ENV}`,
+  // Don't include `.env.local` for `test` environment
+  // since normally you expect tests to produce the same
+  // results for everyone
+  NODE_ENV !== 'test' && `${paths.dotenv}.local`,
+  paths.dotenv,
+].filter(Boolean);
+
+// Load environment variables from .env* files. Suppress warnings using silent
+// if this file is missing. dotenv will never modify any environment variables
+// that have already been set.
+// https://github.com/motdotla/dotenv
+dotenvFiles.forEach(dotenvFile => {
+  if (fs.existsSync(dotenvFile)) {
+    require('dotenv').config({
+      path: dotenvFile,
+    });
+  }
+});
+
+// We support resolving modules according to `NODE_PATH`.
+// This lets you use absolute paths in imports inside large monorepos:
+// https://github.com/facebookincubator/create-react-app/issues/253.
+// It works similar to `NODE_PATH` in Node itself:
+// https://nodejs.org/api/modules.html#modules_loading_from_the_global_folders
+// Note that unlike in Node, only *relative* paths from `NODE_PATH` are honored.
+// Otherwise, we risk importing Node.js core modules into an app instead of Webpack shims.
+// https://github.com/facebookincubator/create-react-app/issues/1023#issuecomment-265344421
+// We also resolve them to make sure all tools using them work consistently.
+const appDirectory = fs.realpathSync(process.cwd());
+process.env.NODE_PATH = (process.env.NODE_PATH || '')
+  .split(path.delimiter)
+  .filter(folder => folder && !path.isAbsolute(folder))
+  .map(folder => path.resolve(appDirectory, folder))
+  .join(path.delimiter);
+
+// Grab NODE_ENV and REACT_APP_* environment variables and prepare them to be
+// injected into the application via DefinePlugin in Webpack configuration.
+const REACT_APP = /^REACT_APP_/i;
+
+function getClientEnvironment(publicUrl) {
+  const raw = Object.keys(process.env)
+    .filter(key => REACT_APP.test(key))
+    .reduce(
+      (env, key) => {
+        env[key] = process.env[key];
+        return env;
+      },
+      {
+        // Useful for determining whether we’re running in production mode.
+        // Most importantly, it switches React into the correct mode.
+        NODE_ENV: process.env.NODE_ENV || 'development',
+        // Useful for resolving the correct path to static assets in `public`.
+        // For example, <img src={process.env.PUBLIC_URL + '/img/logo.png'} />.
+        // This should only be used as an escape hatch. Normally you would put
+        // images into the `src` and `import` them in code to get their paths.
+        PUBLIC_URL: publicUrl,
+      }
+    );
+  // Stringify all values so we can feed into Webpack DefinePlugin
+  const stringified = {
+    'process.env': Object.keys(raw).reduce((env, key) => {
+      env[key] = JSON.stringify(raw[key]);
+      return env;
+    }, {}),
+  };
+
+  return { raw, stringified };
+}
+
+module.exports = getClientEnvironment;

config/jest/babelTransform.js

@@ -0,0 +1,15 @@
+// @remove-file-on-eject
+/**
+ * Copyright (c) 2014-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+'use strict';
+
+const babelJest = require('babel-jest');
+
+module.exports = babelJest.createTransformer({
+  presets: [require.resolve('babel-preset-react-app')],
+  babelrc: false,
+});

config/jest/cssTransform.js

@@ -0,0 +1,22 @@
+// @remove-on-eject-begin
+/**
+ * Copyright (c) 2014-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+// @remove-on-eject-end
+'use strict';
+
+// This is a custom Jest transformer turning style imports into empty objects.
+// http://facebook.github.io/jest/docs/tutorial-webpack.html
+
+module.exports = {
+  process() {
+    return 'module.exports = {};';
+  },
+  getCacheKey() {
+    // The output is always the same.
+    return 'cssTransform';
+  },
+};

config/jest/fileTransform.js

@@ -0,0 +1,20 @@
+// @remove-on-eject-begin
+/**
+ * Copyright (c) 2014-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+// @remove-on-eject-end
+'use strict';
+
+const path = require('path');
+
+// This is a custom Jest transformer turning file imports into filenames.
+// http://facebook.github.io/jest/docs/tutorial-webpack.html
+
+module.exports = {
+  process(src, filename) {
+    return `module.exports = ${JSON.stringify(path.basename(filename))};`;
+  },
+};

config/paths.js

@@ -0,0 +1,118 @@
+// @remove-on-eject-begin
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+// @remove-on-eject-end
+'use strict';
+
+const path = require('path');
+const fs = require('fs');
+const url = require('url');
+
+// Make sure any symlinks in the project folder are resolved:
+// https://github.com/facebookincubator/create-react-app/issues/637
+const appDirectory = fs.realpathSync(process.cwd());
+const resolveApp = relativePath => path.resolve(appDirectory, relativePath);
+
+const envPublicUrl = process.env.PUBLIC_URL;
+
+function ensureSlash(path, needsSlash) {
+  const hasSlash = path.endsWith('/');
+  if (hasSlash && !needsSlash) {
+    return path.substr(path, path.length - 1);
+  } else if (!hasSlash && needsSlash) {
+    return `${path}/`;
+  } else {
+    return path;
+  }
+}
+
+const getPublicUrl = appPackageJson =>
+  envPublicUrl || require(appPackageJson).homepage;
+
+// We use `PUBLIC_URL` environment variable or "homepage" field to infer
+// "public path" at which the app is served.
+// Webpack needs to know it to put the right <script> hrefs into HTML even in
+// single-page apps that may serve index.html for nested URLs like /todos/42.
+// We can't use a relative path in HTML because we don't want to load something
+// like /todos/42/static/js/bundle.7289d.js. We have to know the root.
+function getServedPath(appPackageJson) {
+  const publicUrl = getPublicUrl(appPackageJson);
+  const servedUrl =
+    envPublicUrl || (publicUrl ? url.parse(publicUrl).pathname : '/');
+  return ensureSlash(servedUrl, true);
+}
+
+// config after eject: we're in ./config/
+module.exports = {
+  dotenv: resolveApp('.env'),
+  appBuild: resolveApp('build'),
+  appPublic: resolveApp('public'),
+  appHtml: resolveApp('public/index.html'),
+  appIndexJs: resolveApp('src/index.js'),
+  appPackageJson: resolveApp('package.json'),
+  appSrc: resolveApp('src'),
+  yarnLockFile: resolveApp('yarn.lock'),
+  testsSetup: resolveApp('src/setupTests.js'),
+  appNodeModules: resolveApp('node_modules'),
+  publicUrl: getPublicUrl(resolveApp('package.json')),
+  servedPath: getServedPath(resolveApp('package.json')),
+};
+
+// @remove-on-eject-begin
+const resolveOwn = relativePath => path.resolve(__dirname, '..', relativePath);
+
+// config before eject: we're in ./node_modules/react-scripts/config/
+module.exports = {
+  dotenv: resolveApp('.env'),
+  appPath: resolveApp('.'),
+  appBuild: resolveApp('build'),
+  appPublic: resolveApp('public'),
+  appHtml: resolveApp('public/index.html'),
+  appIndexJs: resolveApp('src/index.js'),
+  appPackageJson: resolveApp('package.json'),
+  appSrc: resolveApp('src'),
+  yarnLockFile: resolveApp('yarn.lock'),
+  testsSetup: resolveApp('src/setupTests.js'),
+  appNodeModules: resolveApp('node_modules'),
+  publicUrl: getPublicUrl(resolveApp('package.json')),
+  servedPath: getServedPath(resolveApp('package.json')),
+  // These properties only exist before ejecting:
+  ownPath: resolveOwn('.'),
+  ownNodeModules: resolveOwn('node_modules'), // This is empty on npm 3
+};
+
+const ownPackageJson = require('../package.json');
+const reactScriptsPath = resolveApp(`node_modules/${ownPackageJson.name}`);
+const reactScriptsLinked =
+  fs.existsSync(reactScriptsPath) &&
+  fs.lstatSync(reactScriptsPath).isSymbolicLink();
+
+// config before publish: we're in ./packages/react-scripts/config/
+if (
+  !reactScriptsLinked &&
+  __dirname.indexOf(path.join('packages', 'react-scripts', 'config')) !== -1
+) {
+  module.exports = {
+    dotenv: resolveOwn('template/.env'),
+    appPath: resolveApp('.'),
+    appBuild: resolveOwn('../../build'),
+    appPublic: resolveOwn('template/public'),
+    appHtml: resolveOwn('template/public/index.html'),
+    appIndexJs: resolveOwn('template/src/index.js'),
+    appPackageJson: resolveOwn('package.json'),
+    appSrc: resolveOwn('template/src'),
+    yarnLockFile: resolveOwn('template/yarn.lock'),
+    testsSetup: resolveOwn('template/src/setupTests.js'),
+    appNodeModules: resolveOwn('node_modules'),
+    publicUrl: getPublicUrl(resolveOwn('package.json')),
+    servedPath: getServedPath(resolveOwn('package.json')),
+    // These properties only exist before ejecting:
+    ownPath: resolveOwn('.'),
+    ownNodeModules: resolveOwn('node_modules'),
+  };
+}
+// @remove-on-eject-end

config/polyfills.js

@@ -0,0 +1,24 @@
+// @remove-on-eject-begin
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+// @remove-on-eject-end
+'use strict';
+
+if (typeof Promise === 'undefined') {
+  // Rejection tracking prevents a common issue where React gets into an
+  // inconsistent state due to an error, but it gets swallowed by a Promise,
+  // and the user has no idea what causes React's erratic future behavior.
+  require('promise/lib/rejection-tracking').enable();
+  window.Promise = require('promise/lib/es6-extensions.js');
+}
+
+// fetch() polyfill for making API calls.
+require('whatwg-fetch');
+
+// Object.assign() is commonly used with React.
+// It will use the native implementation if it's present and isn't buggy.
+Object.assign = require('object-assign');