From ee59eb9b3011e951cd67e23a67efe98d866098f0 Mon Sep 17 00:00:00 2001
From: William Chargin <wchargin@gmail.com>
Date: Sat, 17 Feb 2018 13:28:47 -0800
Subject: [PATCH] Eject from create-react-app (#19)

Summary:
This commit was created by performing the following steps:
  - `rm -r node_modules`
  - `yarn install`
  - `yarn eject`
  - `rm -r node_modules`
  - `yarn install`
on an environment wit Node v6.11.1.

The final `rm -r node_modules && yarn install` ensures that the
`yarn.lock` file is updated accordingly.

Test Plan:
`yarn test`, `yarn flow`, and `yarn start` all still do the right thing.

wchargin-branch: eject
---
 explorer/config/env.js                     |  93 ++++++
 explorer/config/jest/cssTransform.js       |  14 +
 explorer/config/jest/fileTransform.js      |  12 +
 explorer/config/paths.js                   |  55 ++++
 explorer/config/polyfills.js               |  22 ++
 explorer/config/webpack.config.dev.js      | 262 ++++++++++++++++
 explorer/config/webpack.config.prod.js     | 342 +++++++++++++++++++++
 explorer/config/webpackDevServer.config.js |  95 ++++++
 explorer/package.json                      |  89 +++++-
 explorer/scripts/build.js                  | 150 +++++++++
 explorer/scripts/start.js                  | 107 +++++++
 explorer/scripts/test.js                   |  27 ++
 explorer/yarn.lock                         |  53 +---
 13 files changed, 1263 insertions(+), 58 deletions(-)
 create mode 100644 explorer/config/env.js
 create mode 100644 explorer/config/jest/cssTransform.js
 create mode 100644 explorer/config/jest/fileTransform.js
 create mode 100644 explorer/config/paths.js
 create mode 100644 explorer/config/polyfills.js
 create mode 100644 explorer/config/webpack.config.dev.js
 create mode 100644 explorer/config/webpack.config.prod.js
 create mode 100644 explorer/config/webpackDevServer.config.js
 create mode 100644 explorer/scripts/build.js
 create mode 100644 explorer/scripts/start.js
 create mode 100644 explorer/scripts/test.js

diff --git a/explorer/config/env.js b/explorer/config/env.js
new file mode 100644
index 0000000..30a6c7f
--- /dev/null
+++ b/explorer/config/env.js
@@ -0,0 +1,93 @@
+'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.  Variable expansion is supported in .env files.
+// https://github.com/motdotla/dotenv
+// https://github.com/motdotla/dotenv-expand
+dotenvFiles.forEach(dotenvFile => {
+  if (fs.existsSync(dotenvFile)) {
+    require('dotenv-expand')(
+      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;
diff --git a/explorer/config/jest/cssTransform.js b/explorer/config/jest/cssTransform.js
new file mode 100644
index 0000000..8f65114
--- /dev/null
+++ b/explorer/config/jest/cssTransform.js
@@ -0,0 +1,14 @@
+'use strict';
+
+// This is a custom Jest transformer turning style imports into empty objects.
+// http://facebook.github.io/jest/docs/en/webpack.html
+
+module.exports = {
+  process() {
+    return 'module.exports = {};';
+  },
+  getCacheKey() {
+    // The output is always the same.
+    return 'cssTransform';
+  },
+};
diff --git a/explorer/config/jest/fileTransform.js b/explorer/config/jest/fileTransform.js
new file mode 100644
index 0000000..9e4047d
--- /dev/null
+++ b/explorer/config/jest/fileTransform.js
@@ -0,0 +1,12 @@
+'use strict';
+
+const path = require('path');
+
+// This is a custom Jest transformer turning file imports into filenames.
+// http://facebook.github.io/jest/docs/en/webpack.html
+
+module.exports = {
+  process(src, filename) {
+    return `module.exports = ${JSON.stringify(path.basename(filename))};`;
+  },
+};
diff --git a/explorer/config/paths.js b/explorer/config/paths.js
new file mode 100644
index 0000000..6d16efc
--- /dev/null
+++ b/explorer/config/paths.js
@@ -0,0 +1,55 @@
+'use strict';
+
+const path = require('path');
+const fs = require('fs');
+const url = require('url');
+
+// Make sure any symlinks in the project folder are resolved:
+// https://github.com/facebookincubator/create-react-app/issues/637
+const appDirectory = fs.realpathSync(process.cwd());
+const resolveApp = relativePath => path.resolve(appDirectory, relativePath);
+
+const envPublicUrl = process.env.PUBLIC_URL;
+
+function ensureSlash(path, needsSlash) {
+  const hasSlash = path.endsWith('/');
+  if (hasSlash && !needsSlash) {
+    return path.substr(path, path.length - 1);
+  } else if (!hasSlash && needsSlash) {
+    return `${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')),
+};
diff --git a/explorer/config/polyfills.js b/explorer/config/polyfills.js
new file mode 100644
index 0000000..66dff0a
--- /dev/null
+++ b/explorer/config/polyfills.js
@@ -0,0 +1,22 @@
+'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');
+
+// In tests, polyfill requestAnimationFrame since jsdom doesn't provide it yet.
+// We don't polyfill it in the browser--this is user's responsibility.
+if (process.env.NODE_ENV === 'test') {
+  require('raf').polyfill(global);
+}
diff --git a/explorer/config/webpack.config.dev.js b/explorer/config/webpack.config.dev.js
new file mode 100644
index 0000000..740a444
--- /dev/null
+++ b/explorer/config/webpack.config.dev.js
@@ -0,0 +1,262 @@
+'use strict';
+
+const autoprefixer = require('autoprefixer');
+const path = require('path');
+const webpack = require('webpack');
+const HtmlWebpackPlugin = require('html-webpack-plugin');
+const CaseSensitivePathsPlugin = require('case-sensitive-paths-webpack-plugin');
+const InterpolateHtmlPlugin = require('react-dev-utils/InterpolateHtmlPlugin');
+const WatchMissingNodeModulesPlugin = require('react-dev-utils/WatchMissingNodeModulesPlugin');
+const eslintFormatter = require('react-dev-utils/eslintFormatter');
+const ModuleScopePlugin = require('react-dev-utils/ModuleScopePlugin');
+const getClientEnvironment = require('./env');
+const paths = require('./paths');
+
+// Webpack uses `publicPath` to determine where the app is being served from.
+// In development, we always serve from the root. This makes config easier.
+const publicPath = '/';
+// `publicUrl` is just like `publicPath`, but we will provide it to our app
+// as %PUBLIC_URL% in `index.html` and `process.env.PUBLIC_URL` in JavaScript.
+// Omit trailing slash as %PUBLIC_PATH%/xyz looks better than %PUBLIC_PATH%xyz.
+const publicUrl = '';
+// Get environment variables to inject into our app.
+const env = getClientEnvironment(publicUrl);
+
+// This is the development configuration.
+// It is focused on developer experience and fast rebuilds.
+// The production configuration is different and lives in a separate file.
+module.exports = {
+  // You may want 'eval' instead if you prefer to see the compiled output in DevTools.
+  // See the discussion in https://github.com/facebookincubator/create-react-app/issues/343.
+  devtool: 'cheap-module-source-map',
+  // These are the "entry points" to our application.
+  // This means they will be the "root" imports that are included in JS bundle.
+  // The first two entry points enable "hot" CSS and auto-refreshes for JS.
+  entry: [
+    // We ship a few polyfills by default:
+    require.resolve('./polyfills'),
+    // Include an alternative client for WebpackDevServer. A client's job is to
+    // connect to WebpackDevServer by a socket and get notified about changes.
+    // When you save a file, the client will either apply hot updates (in case
+    // of CSS changes), or refresh the page (in case of JS changes). When you
+    // make a syntax error, this client will display a syntax error overlay.
+    // Note: instead of the default WebpackDevServer client, we use a custom one
+    // to bring better experience for Create React App users. You can replace
+    // the line below with these two lines if you prefer the stock client:
+    // require.resolve('webpack-dev-server/client') + '?/',
+    // require.resolve('webpack/hot/dev-server'),
+    require.resolve('react-dev-utils/webpackHotDevClient'),
+    // Finally, this is your app's code:
+    paths.appIndexJs,
+    // We include the app code last so that if there is a runtime error during
+    // initialization, it doesn't blow up the WebpackDevServer client, and
+    // changing JS code would still trigger a refresh.
+  ],
+  output: {
+    // Add /* filename */ comments to generated require()s in the output.
+    pathinfo: true,
+    // This does not produce a real file. It's just the virtual path that is
+    // served by WebpackDevServer in development. This is the JS bundle
+    // containing code from all our entry points, and the Webpack runtime.
+    filename: 'static/js/bundle.js',
+    // There are also additional JS chunk files if you use code splitting.
+    chunkFilename: 'static/js/[name].chunk.js',
+    // This is the URL that app is served from. We use "/" in development.
+    publicPath: publicPath,
+    // Point sourcemap entries to original disk location (format as URL on Windows)
+    devtoolModuleFilenameTemplate: info =>
+      path.resolve(info.absoluteResourcePath).replace(/\\/g, '/'),
+  },
+  resolve: {
+    // This allows you to set a fallback for where Webpack should look for modules.
+    // We placed these paths second because we want `node_modules` to "win"
+    // if there are any conflicts. This matches Node resolution mechanism.
+    // https://github.com/facebookincubator/create-react-app/issues/253
+    modules: ['node_modules', paths.appNodeModules].concat(
+      // It is guaranteed to exist because we tweak it in `env.js`
+      process.env.NODE_PATH.split(path.delimiter).filter(Boolean)
+    ),
+    // These are the reasonable defaults supported by the Node ecosystem.
+    // We also include JSX as a common component filename extension to support
+    // some tools, although we do not recommend using it, see:
+    // https://github.com/facebookincubator/create-react-app/issues/290
+    // `web` extension prefixes have been added for better support
+    // for React Native Web.
+    extensions: ['.web.js', '.mjs', '.js', '.json', '.web.jsx', '.jsx'],
+    alias: {
+      
+      // Support React Native Web
+      // https://www.smashingmagazine.com/2016/08/a-glimpse-into-the-future-with-react-native-for-web/
+      'react-native': 'react-native-web',
+    },
+    plugins: [
+      // Prevents users from importing files from outside of src/ (or node_modules/).
+      // This often causes confusion because we only process files within src/ with babel.
+      // To fix this, we prevent you from importing files out of src/ -- if you'd like to,
+      // please link the files into your node_modules/ and let module-resolution kick in.
+      // Make sure your source files are compiled, as they will not be processed in any way.
+      new ModuleScopePlugin(paths.appSrc, [paths.appPackageJson]),
+    ],
+  },
+  module: {
+    strictExportPresence: true,
+    rules: [
+      // TODO: Disable require.ensure as it's not a standard language feature.
+      // We are waiting for https://github.com/facebookincubator/create-react-app/issues/2176.
+      // { parser: { requireEnsure: false } },
+
+      // First, run the linter.
+      // It's important to do this before Babel processes the JS.
+      {
+        test: /\.(js|jsx|mjs)$/,
+        enforce: 'pre',
+        use: [
+          {
+            options: {
+              formatter: eslintFormatter,
+              eslintPath: require.resolve('eslint'),
+              
+            },
+            loader: require.resolve('eslint-loader'),
+          },
+        ],
+        include: paths.appSrc,
+      },
+      {
+        // "oneOf" will traverse all following loaders until one will
+        // match the requirements. When no loader matches it will fall
+        // back to the "file" loader at the end of the loader list.
+        oneOf: [
+          // "url" loader works like "file" loader except that it embeds assets
+          // smaller than specified limit in bytes as data URLs to avoid requests.
+          // A missing `test` is equivalent to a match.
+          {
+            test: [/\.bmp$/, /\.gif$/, /\.jpe?g$/, /\.png$/],
+            loader: require.resolve('url-loader'),
+            options: {
+              limit: 10000,
+              name: 'static/media/[name].[hash:8].[ext]',
+            },
+          },
+          // Process JS with Babel.
+          {
+            test: /\.(js|jsx|mjs)$/,
+            include: paths.appSrc,
+            loader: require.resolve('babel-loader'),
+            options: {
+              
+              // This is a feature of `babel-loader` for webpack (not Babel itself).
+              // It enables caching results in ./node_modules/.cache/babel-loader/
+              // directory for faster rebuilds.
+              cacheDirectory: true,
+            },
+          },
+          // "postcss" loader applies autoprefixer to our CSS.
+          // "css" loader resolves paths in CSS and adds assets as dependencies.
+          // "style" loader turns CSS into JS modules that inject <style> tags.
+          // In production, we use a plugin to extract that CSS to a file, but
+          // in development "style" loader enables hot editing of CSS.
+          {
+            test: /\.css$/,
+            use: [
+              require.resolve('style-loader'),
+              {
+                loader: require.resolve('css-loader'),
+                options: {
+                  importLoaders: 1,
+                },
+              },
+              {
+                loader: require.resolve('postcss-loader'),
+                options: {
+                  // Necessary for external CSS imports to work
+                  // https://github.com/facebookincubator/create-react-app/issues/2677
+                  ident: 'postcss',
+                  plugins: () => [
+                    require('postcss-flexbugs-fixes'),
+                    autoprefixer({
+                      browsers: [
+                        '>1%',
+                        'last 4 versions',
+                        'Firefox ESR',
+                        'not ie < 9', // React doesn't support IE8 anyway
+                      ],
+                      flexbox: 'no-2009',
+                    }),
+                  ],
+                },
+              },
+            ],
+          },
+          // "file" loader makes sure those assets get served by WebpackDevServer.
+          // When you `import` an asset, you get its (virtual) filename.
+          // In production, they would get copied to the `build` folder.
+          // This loader doesn't use a "test" so it will catch all modules
+          // that fall through the other loaders.
+          {
+            // Exclude `js` files to keep "css" loader working as it injects
+            // its runtime that would otherwise processed through "file" loader.
+            // Also exclude `html` and `json` extensions so they get processed
+            // by webpacks internal loaders.
+            exclude: [/\.(js|jsx|mjs)$/, /\.html$/, /\.json$/],
+            loader: require.resolve('file-loader'),
+            options: {
+              name: 'static/media/[name].[hash:8].[ext]',
+            },
+          },
+        ],
+      },
+      // ** STOP ** Are you adding a new loader?
+      // Make sure to add the new loader(s) before the "file" loader.
+    ],
+  },
+  plugins: [
+    // Makes some environment variables available in index.html.
+    // The public URL is available as %PUBLIC_URL% in index.html, e.g.:
+    // <link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">
+    // In development, this will be an empty string.
+    new InterpolateHtmlPlugin(env.raw),
+    // Generates an `index.html` file with the <script> injected.
+    new HtmlWebpackPlugin({
+      inject: true,
+      template: paths.appHtml,
+    }),
+    // Add module names to factory functions so they appear in browser profiler.
+    new webpack.NamedModulesPlugin(),
+    // Makes some environment variables available to the JS code, for example:
+    // if (process.env.NODE_ENV === 'development') { ... }. See `./env.js`.
+    new webpack.DefinePlugin(env.stringified),
+    // This is necessary to emit hot updates (currently CSS only):
+    new webpack.HotModuleReplacementPlugin(),
+    // Watcher doesn't work well if you mistype casing in a path so we use
+    // a plugin that prints an error when you attempt to do this.
+    // See https://github.com/facebookincubator/create-react-app/issues/240
+    new CaseSensitivePathsPlugin(),
+    // If you require a missing module and then `npm install` it, you still have
+    // to restart the development server for Webpack to discover it. This plugin
+    // makes the discovery automatic so you don't have to restart.
+    // See https://github.com/facebookincubator/create-react-app/issues/186
+    new WatchMissingNodeModulesPlugin(paths.appNodeModules),
+    // Moment.js is an extremely popular library that bundles large locale files
+    // by default due to how Webpack interprets its code. This is a practical
+    // solution that requires the user to opt into importing specific locales.
+    // https://github.com/jmblog/how-to-optimize-momentjs-with-webpack
+    // You can remove this if you don't use Moment.js:
+    new webpack.IgnorePlugin(/^\.\/locale$/, /moment$/),
+  ],
+  // Some libraries import Node modules but don't use them in the browser.
+  // Tell Webpack to provide empty mocks for them so importing them works.
+  node: {
+    dgram: 'empty',
+    fs: 'empty',
+    net: 'empty',
+    tls: 'empty',
+    child_process: 'empty',
+  },
+  // Turn off performance hints during development because we don't do any
+  // splitting or minification in interest of speed. These warnings become
+  // cumbersome.
+  performance: {
+    hints: false,
+  },
+};
diff --git a/explorer/config/webpack.config.prod.js b/explorer/config/webpack.config.prod.js
new file mode 100644
index 0000000..5a89a06
--- /dev/null
+++ b/explorer/config/webpack.config.prod.js
@@ -0,0 +1,342 @@
+'use strict';
+
+const autoprefixer = require('autoprefixer');
+const path = require('path');
+const webpack = require('webpack');
+const HtmlWebpackPlugin = require('html-webpack-plugin');
+const ExtractTextPlugin = require('extract-text-webpack-plugin');
+const ManifestPlugin = require('webpack-manifest-plugin');
+const InterpolateHtmlPlugin = require('react-dev-utils/InterpolateHtmlPlugin');
+const SWPrecacheWebpackPlugin = require('sw-precache-webpack-plugin');
+const eslintFormatter = require('react-dev-utils/eslintFormatter');
+const ModuleScopePlugin = require('react-dev-utils/ModuleScopePlugin');
+const paths = require('./paths');
+const getClientEnvironment = require('./env');
+
+// Webpack uses `publicPath` to determine where the app is being served from.
+// It requires a trailing slash, or the file assets will get an incorrect path.
+const publicPath = paths.servedPath;
+// Some apps do not use client-side routing with pushState.
+// For these, "homepage" can be set to "." to enable relative asset paths.
+const shouldUseRelativeAssetPaths = publicPath === './';
+// Source maps are resource heavy and can cause out of memory issue for large source files.
+const shouldUseSourceMap = process.env.GENERATE_SOURCEMAP !== 'false';
+// `publicUrl` is just like `publicPath`, but we will provide it to our app
+// as %PUBLIC_URL% in `index.html` and `process.env.PUBLIC_URL` in JavaScript.
+// Omit trailing slash as %PUBLIC_URL%/xyz looks better than %PUBLIC_URL%xyz.
+const publicUrl = publicPath.slice(0, -1);
+// Get environment variables to inject into our app.
+const env = getClientEnvironment(publicUrl);
+
+// Assert this just to be safe.
+// Development builds of React are slow and not intended for production.
+if (env.stringified['process.env'].NODE_ENV !== '"production"') {
+  throw new Error('Production builds must have NODE_ENV=production.');
+}
+
+// Note: defined here because it will be used more than once.
+const cssFilename = 'static/css/[name].[contenthash:8].css';
+
+// ExtractTextPlugin expects the build output to be flat.
+// (See https://github.com/webpack-contrib/extract-text-webpack-plugin/issues/27)
+// However, our output is structured with css, js and media folders.
+// To have this structure working with relative paths, we have to use custom options.
+const extractTextPluginOptions = shouldUseRelativeAssetPaths
+  ? // Making sure that the publicPath goes back to to build folder.
+    { publicPath: Array(cssFilename.split('/').length).join('../') }
+  : {};
+
+// This is the production configuration.
+// It compiles slowly and is focused on producing a fast and minimal bundle.
+// The development configuration is different and lives in a separate file.
+module.exports = {
+  // Don't attempt to continue if there are any errors.
+  bail: true,
+  // We generate sourcemaps in production. This is slow but gives good results.
+  // You can exclude the *.map files from the build during deployment.
+  devtool: shouldUseSourceMap ? 'source-map' : false,
+  // In production, we only want to load the polyfills and the app code.
+  entry: [require.resolve('./polyfills'), paths.appIndexJs],
+  output: {
+    // The build folder.
+    path: paths.appBuild,
+    // Generated JS file names (with nested folders).
+    // There will be one main bundle, and one file per asynchronous chunk.
+    // We don't currently advertise code splitting but Webpack supports it.
+    filename: 'static/js/[name].[chunkhash:8].js',
+    chunkFilename: 'static/js/[name].[chunkhash:8].chunk.js',
+    // We inferred the "public path" (such as / or /my-project) from homepage.
+    publicPath: publicPath,
+    // Point sourcemap entries to original disk location (format as URL on Windows)
+    devtoolModuleFilenameTemplate: info =>
+      path
+        .relative(paths.appSrc, info.absoluteResourcePath)
+        .replace(/\\/g, '/'),
+  },
+  resolve: {
+    // This allows you to set a fallback for where Webpack should look for modules.
+    // We placed these paths second because we want `node_modules` to "win"
+    // if there are any conflicts. This matches Node resolution mechanism.
+    // https://github.com/facebookincubator/create-react-app/issues/253
+    modules: ['node_modules', paths.appNodeModules].concat(
+      // It is guaranteed to exist because we tweak it in `env.js`
+      process.env.NODE_PATH.split(path.delimiter).filter(Boolean)
+    ),
+    // These are the reasonable defaults supported by the Node ecosystem.
+    // We also include JSX as a common component filename extension to support
+    // some tools, although we do not recommend using it, see:
+    // https://github.com/facebookincubator/create-react-app/issues/290
+    // `web` extension prefixes have been added for better support
+    // for React Native Web.
+    extensions: ['.web.js', '.mjs', '.js', '.json', '.web.jsx', '.jsx'],
+    alias: {
+      
+      // Support React Native Web
+      // https://www.smashingmagazine.com/2016/08/a-glimpse-into-the-future-with-react-native-for-web/
+      'react-native': 'react-native-web',
+    },
+    plugins: [
+      // Prevents users from importing files from outside of src/ (or node_modules/).
+      // This often causes confusion because we only process files within src/ with babel.
+      // To fix this, we prevent you from importing files out of src/ -- if you'd like to,
+      // please link the files into your node_modules/ and let module-resolution kick in.
+      // Make sure your source files are compiled, as they will not be processed in any way.
+      new ModuleScopePlugin(paths.appSrc, [paths.appPackageJson]),
+    ],
+  },
+  module: {
+    strictExportPresence: true,
+    rules: [
+      // TODO: Disable require.ensure as it's not a standard language feature.
+      // We are waiting for https://github.com/facebookincubator/create-react-app/issues/2176.
+      // { parser: { requireEnsure: false } },
+
+      // First, run the linter.
+      // It's important to do this before Babel processes the JS.
+      {
+        test: /\.(js|jsx|mjs)$/,
+        enforce: 'pre',
+        use: [
+          {
+            options: {
+              formatter: eslintFormatter,
+              eslintPath: require.resolve('eslint'),
+              
+            },
+            loader: require.resolve('eslint-loader'),
+          },
+        ],
+        include: paths.appSrc,
+      },
+      {
+        // "oneOf" will traverse all following loaders until one will
+        // match the requirements. When no loader matches it will fall
+        // back to the "file" loader at the end of the loader list.
+        oneOf: [
+          // "url" loader works just like "file" loader but it also embeds
+          // assets smaller than specified size as data URLs to avoid requests.
+          {
+            test: [/\.bmp$/, /\.gif$/, /\.jpe?g$/, /\.png$/],
+            loader: require.resolve('url-loader'),
+            options: {
+              limit: 10000,
+              name: 'static/media/[name].[hash:8].[ext]',
+            },
+          },
+          // Process JS with Babel.
+          {
+            test: /\.(js|jsx|mjs)$/,
+            include: paths.appSrc,
+            loader: require.resolve('babel-loader'),
+            options: {
+              
+              compact: true,
+            },
+          },
+          // The notation here is somewhat confusing.
+          // "postcss" loader applies autoprefixer to our CSS.
+          // "css" loader resolves paths in CSS and adds assets as dependencies.
+          // "style" loader normally turns CSS into JS modules injecting <style>,
+          // but unlike in development configuration, we do something different.
+          // `ExtractTextPlugin` first applies the "postcss" and "css" loaders
+          // (second argument), then grabs the result CSS and puts it into a
+          // separate file in our build process. This way we actually ship
+          // a single CSS file in production instead of JS code injecting <style>
+          // tags. If you use code splitting, however, any async bundles will still
+          // use the "style" loader inside the async code so CSS from them won't be
+          // in the main CSS file.
+          {
+            test: /\.css$/,
+            loader: ExtractTextPlugin.extract(
+              Object.assign(
+                {
+                  fallback: {
+                    loader: require.resolve('style-loader'),
+                    options: {
+                      hmr: false,
+                    },
+                  },
+                  use: [
+                    {
+                      loader: require.resolve('css-loader'),
+                      options: {
+                        importLoaders: 1,
+                        minimize: true,
+                        sourceMap: shouldUseSourceMap,
+                      },
+                    },
+                    {
+                      loader: require.resolve('postcss-loader'),
+                      options: {
+                        // Necessary for external CSS imports to work
+                        // https://github.com/facebookincubator/create-react-app/issues/2677
+                        ident: 'postcss',
+                        plugins: () => [
+                          require('postcss-flexbugs-fixes'),
+                          autoprefixer({
+                            browsers: [
+                              '>1%',
+                              'last 4 versions',
+                              'Firefox ESR',
+                              'not ie < 9', // React doesn't support IE8 anyway
+                            ],
+                            flexbox: 'no-2009',
+                          }),
+                        ],
+                      },
+                    },
+                  ],
+                },
+                extractTextPluginOptions
+              )
+            ),
+            // Note: this won't work without `new ExtractTextPlugin()` in `plugins`.
+          },
+          // "file" loader makes sure assets end up in the `build` folder.
+          // When you `import` an asset, you get its filename.
+          // This loader doesn't use a "test" so it will catch all modules
+          // that fall through the other loaders.
+          {
+            loader: require.resolve('file-loader'),
+            // Exclude `js` files to keep "css" loader working as it injects
+            // it's runtime that would otherwise processed through "file" loader.
+            // Also exclude `html` and `json` extensions so they get processed
+            // by webpacks internal loaders.
+            exclude: [/\.(js|jsx|mjs)$/, /\.html$/, /\.json$/],
+            options: {
+              name: 'static/media/[name].[hash:8].[ext]',
+            },
+          },
+          // ** STOP ** Are you adding a new loader?
+          // Make sure to add the new loader(s) before the "file" loader.
+        ],
+      },
+    ],
+  },
+  plugins: [
+    // Makes some environment variables available in index.html.
+    // The public URL is available as %PUBLIC_URL% in index.html, e.g.:
+    // <link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">
+    // In production, it will be an empty string unless you specify "homepage"
+    // in `package.json`, in which case it will be the pathname of that URL.
+    new InterpolateHtmlPlugin(env.raw),
+    // Generates an `index.html` file with the <script> injected.
+    new HtmlWebpackPlugin({
+      inject: true,
+      template: paths.appHtml,
+      minify: {
+        removeComments: true,
+        collapseWhitespace: true,
+        removeRedundantAttributes: true,
+        useShortDoctype: true,
+        removeEmptyAttributes: true,
+        removeStyleLinkTypeAttributes: true,
+        keepClosingSlash: true,
+        minifyJS: true,
+        minifyCSS: true,
+        minifyURLs: true,
+      },
+    }),
+    // Makes some environment variables available to the JS code, for example:
+    // if (process.env.NODE_ENV === 'production') { ... }. See `./env.js`.
+    // It is absolutely essential that NODE_ENV was set to production here.
+    // Otherwise React will be compiled in the very slow development mode.
+    new webpack.DefinePlugin(env.stringified),
+    // Minify the code.
+    new webpack.optimize.UglifyJsPlugin({
+      compress: {
+        warnings: false,
+        // Disabled because of an issue with Uglify breaking seemingly valid code:
+        // https://github.com/facebookincubator/create-react-app/issues/2376
+        // Pending further investigation:
+        // https://github.com/mishoo/UglifyJS2/issues/2011
+        comparisons: false,
+      },
+      mangle: {
+        safari10: true,
+      },
+      output: {
+        comments: false,
+        // Turned on because emoji and regex is not minified properly using default
+        // https://github.com/facebookincubator/create-react-app/issues/2488
+        ascii_only: true,
+      },
+      sourceMap: shouldUseSourceMap,
+    }),
+    // Note: this won't work without ExtractTextPlugin.extract(..) in `loaders`.
+    new ExtractTextPlugin({
+      filename: cssFilename,
+    }),
+    // Generate a manifest file which contains a mapping of all asset filenames
+    // to their corresponding output file so that tools can pick it up without
+    // having to parse `index.html`.
+    new ManifestPlugin({
+      fileName: 'asset-manifest.json',
+    }),
+    // Generate a service worker script that will precache, and keep up to date,
+    // the HTML & assets that are part of the Webpack build.
+    new SWPrecacheWebpackPlugin({
+      // By default, a cache-busting query parameter is appended to requests
+      // used to populate the caches, to ensure the responses are fresh.
+      // If a URL is already hashed by Webpack, then there is no concern
+      // about it being stale, and the cache-busting can be skipped.
+      dontCacheBustUrlsMatching: /\.\w{8}\./,
+      filename: 'service-worker.js',
+      logger(message) {
+        if (message.indexOf('Total precache size is') === 0) {
+          // This message occurs for every build and is a bit too noisy.
+          return;
+        }
+        if (message.indexOf('Skipping static resource') === 0) {
+          // This message obscures real errors so we ignore it.
+          // https://github.com/facebookincubator/create-react-app/issues/2612
+          return;
+        }
+        console.log(message);
+      },
+      minify: true,
+      // For unknown URLs, fallback to the index page
+      navigateFallback: publicUrl + '/index.html',
+      // Ignores URLs starting from /__ (useful for Firebase):
+      // https://github.com/facebookincubator/create-react-app/issues/2237#issuecomment-302693219
+      navigateFallbackWhitelist: [/^(?!\/__).*/],
+      // Don't precache sourcemaps (they're large) and build asset manifest:
+      staticFileGlobsIgnorePatterns: [/\.map$/, /asset-manifest\.json$/],
+    }),
+    // Moment.js is an extremely popular library that bundles large locale files
+    // by default due to how Webpack interprets its code. This is a practical
+    // solution that requires the user to opt into importing specific locales.
+    // https://github.com/jmblog/how-to-optimize-momentjs-with-webpack
+    // You can remove this if you don't use Moment.js:
+    new webpack.IgnorePlugin(/^\.\/locale$/, /moment$/),
+  ],
+  // Some libraries import Node modules but don't use them in the browser.
+  // Tell Webpack to provide empty mocks for them so importing them works.
+  node: {
+    dgram: 'empty',
+    fs: 'empty',
+    net: 'empty',
+    tls: 'empty',
+    child_process: 'empty',
+  },
+};
diff --git a/explorer/config/webpackDevServer.config.js b/explorer/config/webpackDevServer.config.js
new file mode 100644
index 0000000..f12d315
--- /dev/null
+++ b/explorer/config/webpackDevServer.config.js
@@ -0,0 +1,95 @@
+'use strict';
+
+const errorOverlayMiddleware = require('react-dev-utils/errorOverlayMiddleware');
+const noopServiceWorkerMiddleware = require('react-dev-utils/noopServiceWorkerMiddleware');
+const ignoredFiles = require('react-dev-utils/ignoredFiles');
+const config = require('./webpack.config.dev');
+const paths = require('./paths');
+
+const protocol = process.env.HTTPS === 'true' ? 'https' : 'http';
+const host = process.env.HOST || '0.0.0.0';
+
+module.exports = function(proxy, allowedHost) {
+  return {
+    // WebpackDevServer 2.4.3 introduced a security fix that prevents remote
+    // websites from potentially accessing local content through DNS rebinding:
+    // https://github.com/webpack/webpack-dev-server/issues/887
+    // https://medium.com/webpack/webpack-dev-server-middleware-security-issues-1489d950874a
+    // However, it made several existing use cases such as development in cloud
+    // environment or subdomains in development significantly more complicated:
+    // https://github.com/facebookincubator/create-react-app/issues/2271
+    // https://github.com/facebookincubator/create-react-app/issues/2233
+    // While we're investigating better solutions, for now we will take a
+    // compromise. Since our WDS configuration only serves files in the `public`
+    // folder we won't consider accessing them a vulnerability. However, if you
+    // use the `proxy` feature, it gets more dangerous because it can expose
+    // remote code execution vulnerabilities in backends like Django and Rails.
+    // So we will disable the host check normally, but enable it if you have
+    // specified the `proxy` setting. Finally, we let you override it if you
+    // really know what you're doing with a special environment variable.
+    disableHostCheck:
+      !proxy || process.env.DANGEROUSLY_DISABLE_HOST_CHECK === 'true',
+    // Enable gzip compression of generated files.
+    compress: true,
+    // Silence WebpackDevServer's own logs since they're generally not useful.
+    // It will still show compile warnings and errors with this setting.
+    clientLogLevel: 'none',
+    // By default WebpackDevServer serves physical files from current directory
+    // in addition to all the virtual build products that it serves from memory.
+    // This is confusing because those files won’t automatically be available in
+    // production build folder unless we copy them. However, copying the whole
+    // project directory is dangerous because we may expose sensitive files.
+    // Instead, we establish a convention that only files in `public` directory
+    // get served. Our build script will copy `public` into the `build` folder.
+    // In `index.html`, you can get URL of `public` folder with %PUBLIC_URL%:
+    // <link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">
+    // In JavaScript code, you can access it with `process.env.PUBLIC_URL`.
+    // Note that we only recommend to use `public` folder as an escape hatch
+    // for files like `favicon.ico`, `manifest.json`, and libraries that are
+    // for some reason broken when imported through Webpack. If you just want to
+    // use an image, put it in `src` and `import` it from JavaScript instead.
+    contentBase: paths.appPublic,
+    // By default files from `contentBase` will not trigger a page reload.
+    watchContentBase: true,
+    // Enable hot reloading server. It will provide /sockjs-node/ endpoint
+    // for the WebpackDevServer client so it can learn when the files were
+    // updated. The WebpackDevServer client is included as an entry point
+    // in the Webpack development configuration. Note that only changes
+    // to CSS are currently hot reloaded. JS changes will refresh the browser.
+    hot: true,
+    // It is important to tell WebpackDevServer to use the same "root" path
+    // as we specified in the config. In development, we always serve from /.
+    publicPath: config.output.publicPath,
+    // WebpackDevServer is noisy by default so we emit custom message instead
+    // by listening to the compiler events with `compiler.plugin` calls above.
+    quiet: true,
+    // Reportedly, this avoids CPU overload on some systems.
+    // https://github.com/facebookincubator/create-react-app/issues/293
+    // src/node_modules is not ignored to support absolute imports
+    // https://github.com/facebookincubator/create-react-app/issues/1065
+    watchOptions: {
+      ignored: ignoredFiles(paths.appSrc),
+    },
+    // Enable HTTPS if the HTTPS environment variable is set to 'true'
+    https: protocol === 'https',
+    host: host,
+    overlay: false,
+    historyApiFallback: {
+      // Paths with dots should still use the history fallback.
+      // See https://github.com/facebookincubator/create-react-app/issues/387.
+      disableDotRule: true,
+    },
+    public: allowedHost,
+    proxy,
+    before(app) {
+      // This lets us open files from the runtime error overlay.
+      app.use(errorOverlayMiddleware());
+      // This service worker file is effectively a 'no-op' that will reset any
+      // previous service worker registered for the same host:port combination.
+      // We do this in development to avoid hitting the production cache if
+      // it used the same host and port.
+      // https://github.com/facebookincubator/create-react-app/issues/2272#issuecomment-302832432
+      app.use(noopServiceWorkerMiddleware());
+    },
+  };
+};
diff --git a/explorer/package.json b/explorer/package.json
index 4791b63..c3ce6ff 100644
--- a/explorer/package.json
+++ b/explorer/package.json
@@ -3,16 +3,93 @@
   "version": "0.1.0",
   "private": true,
   "dependencies": {
+    "autoprefixer": "7.1.6",
+    "babel-core": "6.26.0",
+    "babel-eslint": "7.2.3",
+    "babel-jest": "20.0.3",
+    "babel-loader": "7.1.2",
+    "babel-preset-react-app": "^3.1.1",
+    "babel-runtime": "6.26.0",
+    "case-sensitive-paths-webpack-plugin": "2.1.1",
+    "chalk": "1.1.3",
+    "css-loader": "0.28.7",
+    "dotenv": "4.0.0",
+    "dotenv-expand": "4.0.1",
+    "eslint": "4.10.0",
+    "eslint-config-react-app": "^2.1.0",
+    "eslint-loader": "1.9.0",
+    "eslint-plugin-flowtype": "2.39.1",
+    "eslint-plugin-import": "2.8.0",
+    "eslint-plugin-jsx-a11y": "5.1.1",
+    "eslint-plugin-react": "7.4.0",
+    "extract-text-webpack-plugin": "3.0.2",
+    "file-loader": "1.1.5",
     "flow-bin": "^0.65.0",
+    "fs-extra": "3.0.1",
+    "html-webpack-plugin": "2.29.0",
+    "jest": "20.0.4",
+    "object-assign": "4.1.1",
+    "postcss-flexbugs-fixes": "3.2.0",
+    "postcss-loader": "2.0.8",
+    "promise": "8.0.1",
+    "raf": "3.4.0",
     "react": "^16.2.0",
+    "react-dev-utils": "^5.0.0",
     "react-dom": "^16.2.0",
-    "react-scripts": "1.1.0"
+    "style-loader": "0.19.0",
+    "sw-precache-webpack-plugin": "0.11.4",
+    "url-loader": "0.6.2",
+    "webpack": "3.8.1",
+    "webpack-dev-server": "2.9.4",
+    "webpack-manifest-plugin": "1.3.2",
+    "whatwg-fetch": "2.0.3"
   },
   "scripts": {
-    "start": "react-scripts start",
-    "build": "react-scripts build",
-    "test": "react-scripts test --env=jsdom",
-    "flow": "flow",
-    "eject": "react-scripts eject"
+    "start": "node scripts/start.js",
+    "build": "node scripts/build.js",
+    "test": "node scripts/test.js --env=jsdom",
+    "flow": "flow"
+  },
+  "jest": {
+    "collectCoverageFrom": [
+      "src/**/*.{js,jsx,mjs}"
+    ],
+    "setupFiles": [
+      "<rootDir>/config/polyfills.js"
+    ],
+    "testMatch": [
+      "<rootDir>/src/**/__tests__/**/*.{js,jsx,mjs}",
+      "<rootDir>/src/**/?(*.)(spec|test).{js,jsx,mjs}"
+    ],
+    "testEnvironment": "node",
+    "testURL": "http://localhost",
+    "transform": {
+      "^.+\\.(js|jsx|mjs)$": "<rootDir>/node_modules/babel-jest",
+      "^.+\\.css$": "<rootDir>/config/jest/cssTransform.js",
+      "^(?!.*\\.(js|jsx|mjs|css|json)$)": "<rootDir>/config/jest/fileTransform.js"
+    },
+    "transformIgnorePatterns": [
+      "[/\\\\]node_modules[/\\\\].+\\.(js|jsx|mjs)$"
+    ],
+    "moduleNameMapper": {
+      "^react-native$": "react-native-web"
+    },
+    "moduleFileExtensions": [
+      "web.js",
+      "mjs",
+      "js",
+      "json",
+      "web.jsx",
+      "jsx",
+      "node"
+    ]
+  },
+  "babel": {
+    "presets": [
+      "react-app"
+    ]
+  },
+  "eslintConfig": {
+    "extends": "react-app"
   }
 }
diff --git a/explorer/scripts/build.js b/explorer/scripts/build.js
new file mode 100644
index 0000000..5709f48
--- /dev/null
+++ b/explorer/scripts/build.js
@@ -0,0 +1,150 @@
+'use strict';
+
+// Do this as the first thing so that any code reading it knows the right env.
+process.env.BABEL_ENV = 'production';
+process.env.NODE_ENV = 'production';
+
+// Makes the script crash on unhandled rejections instead of silently
+// ignoring them. In the future, promise rejections that are not handled will
+// terminate the Node.js process with a non-zero exit code.
+process.on('unhandledRejection', err => {
+  throw err;
+});
+
+// Ensure environment variables are read.
+require('../config/env');
+
+const path = require('path');
+const chalk = require('chalk');
+const fs = require('fs-extra');
+const webpack = require('webpack');
+const config = require('../config/webpack.config.prod');
+const paths = require('../config/paths');
+const checkRequiredFiles = require('react-dev-utils/checkRequiredFiles');
+const formatWebpackMessages = require('react-dev-utils/formatWebpackMessages');
+const printHostingInstructions = require('react-dev-utils/printHostingInstructions');
+const FileSizeReporter = require('react-dev-utils/FileSizeReporter');
+const printBuildError = require('react-dev-utils/printBuildError');
+
+const measureFileSizesBeforeBuild =
+  FileSizeReporter.measureFileSizesBeforeBuild;
+const printFileSizesAfterBuild = FileSizeReporter.printFileSizesAfterBuild;
+const useYarn = fs.existsSync(paths.yarnLockFile);
+
+// These sizes are pretty large. We'll warn for bundles exceeding them.
+const WARN_AFTER_BUNDLE_GZIP_SIZE = 512 * 1024;
+const WARN_AFTER_CHUNK_GZIP_SIZE = 1024 * 1024;
+
+// Warn and crash if required files are missing
+if (!checkRequiredFiles([paths.appHtml, paths.appIndexJs])) {
+  process.exit(1);
+}
+
+// First, read the current file sizes in build directory.
+// This lets us display how much they changed later.
+measureFileSizesBeforeBuild(paths.appBuild)
+  .then(previousFileSizes => {
+    // Remove all content but keep the directory so that
+    // if you're in it, you don't end up in Trash
+    fs.emptyDirSync(paths.appBuild);
+    // Merge with the public folder
+    copyPublicFolder();
+    // Start the webpack build
+    return build(previousFileSizes);
+  })
+  .then(
+    ({ stats, previousFileSizes, warnings }) => {
+      if (warnings.length) {
+        console.log(chalk.yellow('Compiled with warnings.\n'));
+        console.log(warnings.join('\n\n'));
+        console.log(
+          '\nSearch for the ' +
+            chalk.underline(chalk.yellow('keywords')) +
+            ' to learn more about each warning.'
+        );
+        console.log(
+          'To ignore, add ' +
+            chalk.cyan('// eslint-disable-next-line') +
+            ' to the line before.\n'
+        );
+      } else {
+        console.log(chalk.green('Compiled successfully.\n'));
+      }
+
+      console.log('File sizes after gzip:\n');
+      printFileSizesAfterBuild(
+        stats,
+        previousFileSizes,
+        paths.appBuild,
+        WARN_AFTER_BUNDLE_GZIP_SIZE,
+        WARN_AFTER_CHUNK_GZIP_SIZE
+      );
+      console.log();
+
+      const appPackage = require(paths.appPackageJson);
+      const publicUrl = paths.publicUrl;
+      const publicPath = config.output.publicPath;
+      const buildFolder = path.relative(process.cwd(), paths.appBuild);
+      printHostingInstructions(
+        appPackage,
+        publicUrl,
+        publicPath,
+        buildFolder,
+        useYarn
+      );
+    },
+    err => {
+      console.log(chalk.red('Failed to compile.\n'));
+      printBuildError(err);
+      process.exit(1);
+    }
+  );
+
+// Create the production build and print the deployment instructions.
+function build(previousFileSizes) {
+  console.log('Creating an optimized production build...');
+
+  let compiler = webpack(config);
+  return new Promise((resolve, reject) => {
+    compiler.run((err, stats) => {
+      if (err) {
+        return reject(err);
+      }
+      const messages = formatWebpackMessages(stats.toJson({}, true));
+      if (messages.errors.length) {
+        // Only keep the first error. Others are often indicative
+        // of the same problem, but confuse the reader with noise.
+        if (messages.errors.length > 1) {
+          messages.errors.length = 1;
+        }
+        return reject(new Error(messages.errors.join('\n\n')));
+      }
+      if (
+        process.env.CI &&
+        (typeof process.env.CI !== 'string' ||
+          process.env.CI.toLowerCase() !== 'false') &&
+        messages.warnings.length
+      ) {
+        console.log(
+          chalk.yellow(
+            '\nTreating warnings as errors because process.env.CI = true.\n' +
+              'Most CI servers set it automatically.\n'
+          )
+        );
+        return reject(new Error(messages.warnings.join('\n\n')));
+      }
+      return resolve({
+        stats,
+        previousFileSizes,
+        warnings: messages.warnings,
+      });
+    });
+  });
+}
+
+function copyPublicFolder() {
+  fs.copySync(paths.appPublic, paths.appBuild, {
+    dereference: true,
+    filter: file => file !== paths.appHtml,
+  });
+}
diff --git a/explorer/scripts/start.js b/explorer/scripts/start.js
new file mode 100644
index 0000000..c5acbe5
--- /dev/null
+++ b/explorer/scripts/start.js
@@ -0,0 +1,107 @@
+'use strict';
+
+// Do this as the first thing so that any code reading it knows the right env.
+process.env.BABEL_ENV = 'development';
+process.env.NODE_ENV = 'development';
+
+// Makes the script crash on unhandled rejections instead of silently
+// ignoring them. In the future, promise rejections that are not handled will
+// terminate the Node.js process with a non-zero exit code.
+process.on('unhandledRejection', err => {
+  throw err;
+});
+
+// Ensure environment variables are read.
+require('../config/env');
+
+const fs = require('fs');
+const chalk = require('chalk');
+const webpack = require('webpack');
+const WebpackDevServer = require('webpack-dev-server');
+const clearConsole = require('react-dev-utils/clearConsole');
+const checkRequiredFiles = require('react-dev-utils/checkRequiredFiles');
+const {
+  choosePort,
+  createCompiler,
+  prepareProxy,
+  prepareUrls,
+} = require('react-dev-utils/WebpackDevServerUtils');
+const openBrowser = require('react-dev-utils/openBrowser');
+const paths = require('../config/paths');
+const config = require('../config/webpack.config.dev');
+const createDevServerConfig = require('../config/webpackDevServer.config');
+
+const useYarn = fs.existsSync(paths.yarnLockFile);
+const isInteractive = process.stdout.isTTY;
+
+// Warn and crash if required files are missing
+if (!checkRequiredFiles([paths.appHtml, paths.appIndexJs])) {
+  process.exit(1);
+}
+
+// Tools like Cloud9 rely on this.
+const DEFAULT_PORT = parseInt(process.env.PORT, 10) || 3000;
+const HOST = process.env.HOST || '0.0.0.0';
+
+if (process.env.HOST) {
+  console.log(
+    chalk.cyan(
+      `Attempting to bind to HOST environment variable: ${chalk.yellow(
+        chalk.bold(process.env.HOST)
+      )}`
+    )
+  );
+  console.log(
+    `If this was unintentional, check that you haven't mistakenly set it in your shell.`
+  );
+  console.log(`Learn more here: ${chalk.yellow('http://bit.ly/2mwWSwH')}`);
+  console.log();
+}
+
+// We attempt to use the default port but if it is busy, we offer the user to
+// run on a different port. `choosePort()` Promise resolves to the next free port.
+choosePort(HOST, DEFAULT_PORT)
+  .then(port => {
+    if (port == null) {
+      // We have not found a port.
+      return;
+    }
+    const protocol = process.env.HTTPS === 'true' ? 'https' : 'http';
+    const appName = require(paths.appPackageJson).name;
+    const urls = prepareUrls(protocol, HOST, port);
+    // Create a webpack compiler that is configured with custom messages.
+    const compiler = createCompiler(webpack, config, appName, urls, useYarn);
+    // Load proxy config
+    const proxySetting = require(paths.appPackageJson).proxy;
+    const proxyConfig = prepareProxy(proxySetting, paths.appPublic);
+    // Serve webpack assets generated by the compiler over a web sever.
+    const serverConfig = createDevServerConfig(
+      proxyConfig,
+      urls.lanUrlForConfig
+    );
+    const devServer = new WebpackDevServer(compiler, serverConfig);
+    // Launch WebpackDevServer.
+    devServer.listen(port, HOST, err => {
+      if (err) {
+        return console.log(err);
+      }
+      if (isInteractive) {
+        clearConsole();
+      }
+      console.log(chalk.cyan('Starting the development server...\n'));
+      openBrowser(urls.localUrlForBrowser);
+    });
+
+    ['SIGINT', 'SIGTERM'].forEach(function(sig) {
+      process.on(sig, function() {
+        devServer.close();
+        process.exit();
+      });
+    });
+  })
+  .catch(err => {
+    if (err && err.message) {
+      console.log(err.message);
+    }
+    process.exit(1);
+  });
diff --git a/explorer/scripts/test.js b/explorer/scripts/test.js
new file mode 100644
index 0000000..399bfd3
--- /dev/null
+++ b/explorer/scripts/test.js
@@ -0,0 +1,27 @@
+'use strict';
+
+// Do this as the first thing so that any code reading it knows the right env.
+process.env.BABEL_ENV = 'test';
+process.env.NODE_ENV = 'test';
+process.env.PUBLIC_URL = '';
+
+// Makes the script crash on unhandled rejections instead of silently
+// ignoring them. In the future, promise rejections that are not handled will
+// terminate the Node.js process with a non-zero exit code.
+process.on('unhandledRejection', err => {
+  throw err;
+});
+
+// Ensure environment variables are read.
+require('../config/env');
+
+const jest = require('jest');
+const argv = process.argv.slice(2);
+
+// Watch unless on CI or in coverage mode
+if (!process.env.CI && argv.indexOf('--coverage') < 0) {
+  argv.push('--watch');
+}
+
+
+jest.run(argv);
diff --git a/explorer/yarn.lock b/explorer/yarn.lock
index 413d06d..019bb7e 100644
--- a/explorer/yarn.lock
+++ b/explorer/yarn.lock
@@ -2660,13 +2660,6 @@ fs.realpath@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/fs.realpath/-/fs.realpath-1.0.0.tgz#1504ad2523158caa40db4a2787cb01411994ea4f"
 
-fsevents@1.1.2:
-  version "1.1.2"
-  resolved "https://registry.yarnpkg.com/fsevents/-/fsevents-1.1.2.tgz#3282b713fb3ad80ede0e9fcf4611b5aa6fc033f4"
-  dependencies:
-    nan "^2.3.0"
-    node-pre-gyp "^0.6.36"
-
 fsevents@^1.0.0:
   version "1.1.3"
   resolved "https://registry.yarnpkg.com/fsevents/-/fsevents-1.1.3.tgz#11f82318f5fe7bb2cd22965a108e9306208216d8"
@@ -4262,7 +4255,7 @@ node-notifier@^5.0.2:
     shellwords "^0.1.1"
     which "^1.3.0"
 
-node-pre-gyp@^0.6.36, node-pre-gyp@^0.6.39:
+node-pre-gyp@^0.6.39:
   version "0.6.39"
   resolved "https://registry.yarnpkg.com/node-pre-gyp/-/node-pre-gyp-0.6.39.tgz#c00e96860b23c0e1420ac7befc5044e1d78d8649"
   dependencies:
@@ -5154,50 +5147,6 @@ react-error-overlay@^4.0.0:
   version "4.0.0"
   resolved "https://registry.yarnpkg.com/react-error-overlay/-/react-error-overlay-4.0.0.tgz#d198408a85b4070937a98667f500c832f86bd5d4"
 
-react-scripts@1.1.0:
-  version "1.1.0"
-  resolved "https://registry.yarnpkg.com/react-scripts/-/react-scripts-1.1.0.tgz#0c94b2b2e14cff2dad8919397901b5edebeba511"
-  dependencies:
-    autoprefixer "7.1.6"
-    babel-core "6.26.0"
-    babel-eslint "7.2.3"
-    babel-jest "20.0.3"
-    babel-loader "7.1.2"
-    babel-preset-react-app "^3.1.1"
-    babel-runtime "6.26.0"
-    case-sensitive-paths-webpack-plugin "2.1.1"
-    chalk "1.1.3"
-    css-loader "0.28.7"
-    dotenv "4.0.0"
-    dotenv-expand "4.0.1"
-    eslint "4.10.0"
-    eslint-config-react-app "^2.1.0"
-    eslint-loader "1.9.0"
-    eslint-plugin-flowtype "2.39.1"
-    eslint-plugin-import "2.8.0"
-    eslint-plugin-jsx-a11y "5.1.1"
-    eslint-plugin-react "7.4.0"
-    extract-text-webpack-plugin "3.0.2"
-    file-loader "1.1.5"
-    fs-extra "3.0.1"
-    html-webpack-plugin "2.29.0"
-    jest "20.0.4"
-    object-assign "4.1.1"
-    postcss-flexbugs-fixes "3.2.0"
-    postcss-loader "2.0.8"
-    promise "8.0.1"
-    raf "3.4.0"
-    react-dev-utils "^5.0.0"
-    style-loader "0.19.0"
-    sw-precache-webpack-plugin "0.11.4"
-    url-loader "0.6.2"
-    webpack "3.8.1"
-    webpack-dev-server "2.9.4"
-    webpack-manifest-plugin "1.3.2"
-    whatwg-fetch "2.0.3"
-  optionalDependencies:
-    fsevents "1.1.2"
-
 react@^16.2.0:
   version "16.2.0"
   resolved "https://registry.yarnpkg.com/react/-/react-16.2.0.tgz#a31bd2dab89bff65d42134fa187f24d054c273ba"