├── public
    ├── favicon.ico
    └── index.html
├── src
    ├── config
    │   └── endpoints.js
    ├── containers
    │   ├── Home.js
    │   ├── Profile.js
    │   └── Template.js
    ├── index.js
    └── routes
    │   └── index.js
├── .gitignore
├── config
    ├── jest
    │   ├── fileTransform.js
    │   └── cssTransform.js
    ├── polyfills.js
    ├── env.js
    ├── paths.js
    ├── webpack.config.dev.js
    └── webpack.config.prod.js
├── scripts
    ├── test.js
    ├── build.js
    └── start.js
├── package.json
└── README.md


/public/favicon.ico:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/discounts/ticturing/master/public/favicon.ico


--------------------------------------------------------------------------------
/src/config/endpoints.js:
--------------------------------------------------------------------------------
1 | export const relayApi = 'https://api.graph.cool/relay/v1/cj1kws33p0gyh0165f43flbmp'
2 | 


--------------------------------------------------------------------------------
/src/containers/Home.js:
--------------------------------------------------------------------------------
 1 | import React, {Component} from 'react'
 2 | 
 3 | class Home extends Component {
 4 | 
 5 |   render() {
 6 |     return (
 7 |       <div>
 8 |       <h2>Home!</h2>
 9 |       </div>
10 |     )
11 |   }
12 | }
13 | 
14 | export default Home
15 | 


--------------------------------------------------------------------------------
/src/containers/Profile.js:
--------------------------------------------------------------------------------
 1 | import React, {Component} from 'react'
 2 | 
 3 | class Profile extends Component {
 4 | 
 5 |   render() {
 6 |     return (
 7 |       <div>
 8 |       <h2>Profile!</h2>
 9 |       </div>
10 |     )
11 |   }
12 | }
13 | 
14 | export default Profile
15 | 


--------------------------------------------------------------------------------
/.gitignore:
--------------------------------------------------------------------------------
 1 | # See https://help.github.com/ignore-files/ for more about ignoring files.
 2 | 
 3 | # dependencies
 4 | /node_modules
 5 | 
 6 | # testing
 7 | /coverage
 8 | 
 9 | # production
10 | /build
11 | 
12 | # misc
13 | .DS_Store
14 | .env
15 | npm-debug.log*
16 | yarn-debug.log*
17 | yarn-error.log*
18 | 
19 | 


--------------------------------------------------------------------------------
/src/index.js:
--------------------------------------------------------------------------------
 1 | import React from 'react'
 2 | import ReactDOM from 'react-dom'
 3 | import {Router, browserHistory} from 'react-router'
 4 | import Routes from './routes'
 5 | 
 6 | ReactDOM.render(
 7 |   <Router
 8 |     history={browserHistory}
 9 |     routes={Routes}
10 |   />,
11 |   document.getElementById('root')
12 | );
13 | 


--------------------------------------------------------------------------------
/config/jest/fileTransform.js:
--------------------------------------------------------------------------------
 1 | 'use strict';
 2 | 
 3 | const path = require('path');
 4 | 
 5 | // This is a custom Jest transformer turning file imports into filenames.
 6 | // http://facebook.github.io/jest/docs/tutorial-webpack.html
 7 | 
 8 | module.exports = {
 9 |   process(src, filename) {
10 |     return 'module.exports = ' + JSON.stringify(path.basename(filename)) + ';';
11 |   },
12 | };
13 | 


--------------------------------------------------------------------------------
/config/jest/cssTransform.js:
--------------------------------------------------------------------------------
 1 | 'use strict';
 2 | 
 3 | // This is a custom Jest transformer turning style imports into empty objects.
 4 | // http://facebook.github.io/jest/docs/tutorial-webpack.html
 5 | 
 6 | module.exports = {
 7 |   process() {
 8 |     return 'module.exports = {};';
 9 |   },
10 |   getCacheKey() {
11 |     // The output is always the same.
12 |     return 'cssTransform';
13 |   },
14 | };
15 | 


--------------------------------------------------------------------------------
/src/routes/index.js:
--------------------------------------------------------------------------------
 1 | import React from 'react'
 2 | import {Route, IndexRoute} from 'react-router'
 3 | import Template from '../containers/Template'
 4 | import Home from '../containers/Home'
 5 | import Profile from '../containers/Profile'
 6 | 
 7 | const createRoutes = () => {
 8 |   return (
 9 |     <Route
10 |        path='/'
11 |        component={Template}
12 |      >
13 |        <IndexRoute
14 |           component={Home}
15 |        />
16 |        <Route
17 |          path={'/profile'}
18 |          component={Profile}
19 |        />
20 |     </Route>
21 |   )
22 | }
23 | 
24 | const Routes = createRoutes()
25 | 
26 | export default Routes
27 | 


--------------------------------------------------------------------------------
/scripts/test.js:
--------------------------------------------------------------------------------
 1 | 'use strict';
 2 | 
 3 | process.env.NODE_ENV = 'test';
 4 | process.env.PUBLIC_URL = '';
 5 | 
 6 | // Load environment variables from .env file. Suppress warnings using silent
 7 | // if this file is missing. dotenv will never modify any environment variables
 8 | // that have already been set.
 9 | // https://github.com/motdotla/dotenv
10 | require('dotenv').config({silent: true});
11 | 
12 | const jest = require('jest');
13 | const argv = process.argv.slice(2);
14 | 
15 | // Watch unless on CI or in coverage mode
16 | if (!process.env.CI && argv.indexOf('--coverage') < 0) {
17 |   argv.push('--watch');
18 | }
19 | 
20 | 
21 | jest.run(argv);
22 | 


--------------------------------------------------------------------------------
/config/polyfills.js:
--------------------------------------------------------------------------------
 1 | 'use strict';
 2 | 
 3 | if (typeof Promise === 'undefined') {
 4 |   // Rejection tracking prevents a common issue where React gets into an
 5 |   // inconsistent state due to an error, but it gets swallowed by a Promise,
 6 |   // and the user has no idea what causes React's erratic future behavior.
 7 |   require('promise/lib/rejection-tracking').enable();
 8 |   window.Promise = require('promise/lib/es6-extensions.js');
 9 | }
10 | 
11 | // fetch() polyfill for making API calls.
12 | require('whatwg-fetch');
13 | 
14 | // Object.assign() is commonly used with React.
15 | // It will use the native implementation if it's present and isn't buggy.
16 | Object.assign = require('object-assign');
17 | 


--------------------------------------------------------------------------------
/src/containers/Template.js:
--------------------------------------------------------------------------------
 1 | import React, {Component} from 'react'
 2 | import MuiThemeProvider from 'material-ui/styles/MuiThemeProvider'
 3 | import injectTapEventPlugin from 'react-tap-event-plugin'
 4 | import RaisedButton from 'material-ui/RaisedButton'
 5 | 
 6 | injectTapEventPlugin()
 7 | 
 8 | class Template extends Component {
 9 | 
10 |   render() {
11 |     return (
12 |       <MuiThemeProvider>
13 |       <div>
14 |         <header>
15 |          <h1>TicTacTuring</h1>
16 |          <RaisedButton
17 |          label={'Test Button'}
18 |          primary={true}
19 |           onTouchTap={()=>{console.log('hello, I work')}}
20 |          />
21 |         </header>
22 |         <main>
23 |           {this.props.children}
24 |         </main>
25 |       </div>
26 |       </MuiThemeProvider>
27 | 
28 |     )
29 |   }
30 | }
31 | 
32 | export default Template
33 | 


--------------------------------------------------------------------------------
/public/index.html:
--------------------------------------------------------------------------------
 1 | <!doctype html>
 2 | <html lang="en">
 3 |   <head>
 4 |     <meta charset="utf-8">
 5 |     <meta name="viewport" content="width=device-width, initial-scale=1">
 6 |     <link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">
 7 |     <!--
 8 |       Notice the use of %PUBLIC_URL% in the tag above.
 9 |       It will be replaced with the URL of the `public` folder during the build.
10 |       Only files inside the `public` folder can be referenced from the HTML.
11 | 
12 |       Unlike "/favicon.ico" or "favicon.ico", "%PUBLIC_URL%/favicon.ico" will
13 |       work correctly both with client-side routing and a non-root public URL.
14 |       Learn how to configure a non-root public URL by running `npm run build`.
15 |     -->
16 |     <title>TicTacTuring</title>
17 |   </head>
18 |   <body>
19 |     <div id="root"></div>
20 |     <!--
21 |       This HTML file is a template.
22 |       If you open it directly in the browser, you will see an empty page.
23 | 
24 |       You can add webfonts, meta tags, or analytics to this file.
25 |       The build step will place the bundled scripts into the <body> tag.
26 | 
27 |       To begin the development, run `npm start`.
28 |       To create a production bundle, use `npm run build`.
29 |     -->
30 |   </body>
31 | </html>
32 | 


--------------------------------------------------------------------------------
/config/env.js:
--------------------------------------------------------------------------------
 1 | 'use strict';
 2 | 
 3 | // Grab NODE_ENV and REACT_APP_* environment variables and prepare them to be
 4 | // injected into the application via DefinePlugin in Webpack configuration.
 5 | 
 6 | var REACT_APP = /^REACT_APP_/i;
 7 | 
 8 | function getClientEnvironment(publicUrl) {
 9 |   var raw = Object
10 |     .keys(process.env)
11 |     .filter(key => REACT_APP.test(key))
12 |     .reduce((env, key) => {
13 |       env[key] = process.env[key];
14 |       return env;
15 |     }, {
16 |       // Useful for determining whether we’re running in production mode.
17 |       // Most importantly, it switches React into the correct mode.
18 |       'NODE_ENV': process.env.NODE_ENV || 'development',
19 |       // Useful for resolving the correct path to static assets in `public`.
20 |       // For example, <img src={process.env.PUBLIC_URL + '/img/logo.png'} />.
21 |       // This should only be used as an escape hatch. Normally you would put
22 |       // images into the `src` and `import` them in code to get their paths.
23 |       'PUBLIC_URL': publicUrl
24 |     });
25 |   // Stringify all values so we can feed into Webpack DefinePlugin
26 |   var stringified = {
27 |     'process.env': Object
28 |       .keys(raw)
29 |       .reduce((env, key) => {
30 |         env[key] = JSON.stringify(raw[key]);
31 |         return env;
32 |       }, {})
33 |   };
34 | 
35 |   return { raw, stringified };
36 | }
37 | 
38 | module.exports = getClientEnvironment;
39 | 


--------------------------------------------------------------------------------
/package.json:
--------------------------------------------------------------------------------
 1 | {
 2 |   "name": "ticturing",
 3 |   "version": "0.1.0",
 4 |   "private": true,
 5 |   "dependencies": {
 6 |     "material-ui": "^0.17.4",
 7 |     "react": "15.4.2",
 8 |     "react-dom": "15.4.2",
 9 |     "react-router": "3.0.2",
10 |     "react-tap-event-plugin": "^2.0.1"
11 |   },
12 |   "devDependencies": {
13 |     "autoprefixer": "6.7.2",
14 |     "babel-core": "6.22.1",
15 |     "babel-eslint": "7.1.1",
16 |     "babel-jest": "18.0.0",
17 |     "babel-loader": "6.2.10",
18 |     "babel-plugin-react-relay": "^0.10.0",
19 |     "babel-preset-react-app": "^2.2.0",
20 |     "babel-runtime": "^6.20.0",
21 |     "case-sensitive-paths-webpack-plugin": "1.1.4",
22 |     "chalk": "1.1.3",
23 |     "connect-history-api-fallback": "1.3.0",
24 |     "cross-spawn": "4.0.2",
25 |     "css-loader": "0.26.1",
26 |     "detect-port": "1.1.0",
27 |     "dotenv": "2.0.0",
28 |     "eslint": "3.8.1",
29 |     "eslint-config-react-app": "0.5.0",
30 |     "eslint-loader": "1.6.0",
31 |     "eslint-plugin-flowtype": "2.21.0",
32 |     "eslint-plugin-import": "2.0.1",
33 |     "eslint-plugin-jsx-a11y": "2.2.3",
34 |     "eslint-plugin-react": "6.4.1",
35 |     "extract-text-webpack-plugin": "1.0.1",
36 |     "file-loader": "0.10.0",
37 |     "fs-extra": "0.30.0",
38 |     "html-webpack-plugin": "2.24.0",
39 |     "http-proxy-middleware": "0.17.3",
40 |     "jest": "17.0.2",
41 |     "json-loader": "0.5.4",
42 |     "object-assign": "4.1.1",
43 |     "postcss-loader": "1.2.2",
44 |     "promise": "7.1.1",
45 |     "react-dev-utils": "0.4.2",
46 |     "recursive-readdir": "2.1.0",
47 |     "strip-ansi": "3.0.1",
48 |     "style-loader": "0.13.1",
49 |     "url-loader": "0.5.7",
50 |     "webpack": "1.14.0",
51 |     "webpack-dev-server": "1.16.2",
52 |     "webpack-manifest-plugin": "1.1.0",
53 |     "whatwg-fetch": "1.0.0"
54 |   },
55 |   "scripts": {
56 |     "start": "GRAPHQL_ENDPOINT=https://api.graph.cool/relay/v1/cj1kws33p0gyh0165f43flbmp node scripts/start.js",
57 |     "build": "GRAPHQL_ENDPOINT=https://api.graph.cool/relay/v1/cj1kws33p0gyh0165f43flbmp node scripts/build.js",
58 |     "test": "node scripts/test.js --env=jsdom"
59 |   },
60 |   "jest": {
61 |     "collectCoverageFrom": [
62 |       "src/**/*.{js,jsx}"
63 |     ],
64 |     "setupFiles": [
65 |       "<rootDir>/config/polyfills.js"
66 |     ],
67 |     "testPathIgnorePatterns": [
68 |       "<rootDir>[/\\\\](build|docs|node_modules|scripts)[/\\\\]"
69 |     ],
70 |     "testEnvironment": "node",
71 |     "testURL": "http://localhost",
72 |     "transform": {
73 |       "^.+\\.(js|jsx)$": "<rootDir>/node_modules/babel-jest",
74 |       "^.+\\.css$": "<rootDir>/config/jest/cssTransform.js",
75 |       "^(?!.*\\.(js|jsx|css|json)$)": "<rootDir>/config/jest/fileTransform.js"
76 |     },
77 |     "transformIgnorePatterns": [
78 |       "[/\\\\]node_modules[/\\\\].+\\.(js|jsx)$"
79 |     ],
80 |     "moduleNameMapper": {
81 |       "^react-native$": "react-native-web"
82 |     }
83 |   },
84 |   "babel": {
85 |     "plugins": [
86 |       "react-relay"
87 |     ],
88 |     "presets": [
89 |       "react-app"
90 |     ]
91 |   },
92 |   "eslintConfig": {
93 |     "extends": "react-app"
94 |   }
95 | }
96 | 


--------------------------------------------------------------------------------
/config/paths.js:
--------------------------------------------------------------------------------
 1 | 'use strict';
 2 | 
 3 | var path = require('path');
 4 | var fs = require('fs');
 5 | var url = require('url');
 6 | 
 7 | // Make sure any symlinks in the project folder are resolved:
 8 | // https://github.com/facebookincubator/create-react-app/issues/637
 9 | var appDirectory = fs.realpathSync(process.cwd());
10 | function resolveApp(relativePath) {
11 |   return path.resolve(appDirectory, relativePath);
12 | }
13 | 
14 | // We support resolving modules according to `NODE_PATH`.
15 | // This lets you use absolute paths in imports inside large monorepos:
16 | // https://github.com/facebookincubator/create-react-app/issues/253.
17 | 
18 | // It works similar to `NODE_PATH` in Node itself:
19 | // https://nodejs.org/api/modules.html#modules_loading_from_the_global_folders
20 | 
21 | // We will export `nodePaths` as an array of absolute paths.
22 | // It will then be used by Webpack configs.
23 | // Jest doesn’t need this because it already handles `NODE_PATH` out of the box.
24 | 
25 | // Note that unlike in Node, only *relative* paths from `NODE_PATH` are honored.
26 | // Otherwise, we risk importing Node.js core modules into an app instead of Webpack shims.
27 | // https://github.com/facebookincubator/create-react-app/issues/1023#issuecomment-265344421
28 | 
29 | var nodePaths = (process.env.NODE_PATH || '')
30 |   .split(process.platform === 'win32' ? ';' : ':')
31 |   .filter(Boolean)
32 |   .filter(folder => !path.isAbsolute(folder))
33 |   .map(resolveApp);
34 | 
35 | var envPublicUrl = process.env.PUBLIC_URL;
36 | 
37 | function ensureSlash(path, needsSlash) {
38 |   var hasSlash = path.endsWith('/');
39 |   if (hasSlash && !needsSlash) {
40 |     return path.substr(path, path.length - 1);
41 |   } else if (!hasSlash && needsSlash) {
42 |     return path + '/';
43 |   } else {
44 |     return path;
45 |   }
46 | }
47 | 
48 | function getPublicUrl(appPackageJson) {
49 |   return envPublicUrl || require(appPackageJson).homepage;
50 | }
51 | 
52 | // We use `PUBLIC_URL` environment variable or "homepage" field to infer
53 | // "public path" at which the app is served.
54 | // Webpack needs to know it to put the right <script> hrefs into HTML even in
55 | // single-page apps that may serve index.html for nested URLs like /todos/42.
56 | // We can't use a relative path in HTML because we don't want to load something
57 | // like /todos/42/static/js/bundle.7289d.js. We have to know the root.
58 | function getServedPath(appPackageJson) {
59 |   var publicUrl = getPublicUrl(appPackageJson);
60 |   var servedUrl = envPublicUrl || (
61 |     publicUrl ? url.parse(publicUrl).pathname : '/'
62 |   );
63 |   return ensureSlash(servedUrl, true);
64 | }
65 | 
66 | // config after eject: we're in ./config/
67 | module.exports = {
68 |   appBuild: resolveApp('build'),
69 |   appPublic: resolveApp('public'),
70 |   appHtml: resolveApp('public/index.html'),
71 |   appIndexJs: resolveApp('src/index.js'),
72 |   appPackageJson: resolveApp('package.json'),
73 |   appSrc: resolveApp('src'),
74 |   yarnLockFile: resolveApp('yarn.lock'),
75 |   testsSetup: resolveApp('src/setupTests.js'),
76 |   appNodeModules: resolveApp('node_modules'),
77 |   nodePaths: nodePaths,
78 |   publicUrl: getPublicUrl(resolveApp('package.json')),
79 |   servedPath: getServedPath(resolveApp('package.json'))
80 | };
81 | 


--------------------------------------------------------------------------------
/scripts/build.js:
--------------------------------------------------------------------------------
  1 | 'use strict';
  2 | 
  3 | // Do this as the first thing so that any code reading it knows the right env.
  4 | process.env.NODE_ENV = 'production';
  5 | 
  6 | // Load environment variables from .env file. Suppress warnings using silent
  7 | // if this file is missing. dotenv will never modify any environment variables
  8 | // that have already been set.
  9 | // https://github.com/motdotla/dotenv
 10 | require('dotenv').config({silent: true});
 11 | 
 12 | var chalk = require('chalk');
 13 | var fs = require('fs-extra');
 14 | var path = require('path');
 15 | var url = require('url');
 16 | var webpack = require('webpack');
 17 | var config = require('../config/webpack.config.prod');
 18 | var paths = require('../config/paths');
 19 | var checkRequiredFiles = require('react-dev-utils/checkRequiredFiles');
 20 | var FileSizeReporter = require('react-dev-utils/FileSizeReporter');
 21 | var measureFileSizesBeforeBuild = FileSizeReporter.measureFileSizesBeforeBuild;
 22 | var printFileSizesAfterBuild = FileSizeReporter.printFileSizesAfterBuild;
 23 | 
 24 | var useYarn = fs.existsSync(paths.yarnLockFile);
 25 | 
 26 | // Warn and crash if required files are missing
 27 | if (!checkRequiredFiles([paths.appHtml, paths.appIndexJs])) {
 28 |   process.exit(1);
 29 | }
 30 | 
 31 | // First, read the current file sizes in build directory.
 32 | // This lets us display how much they changed later.
 33 | measureFileSizesBeforeBuild(paths.appBuild).then(previousFileSizes => {
 34 |   // Remove all content but keep the directory so that
 35 |   // if you're in it, you don't end up in Trash
 36 |   fs.emptyDirSync(paths.appBuild);
 37 | 
 38 |   // Start the webpack build
 39 |   build(previousFileSizes);
 40 | 
 41 |   // Merge with the public folder
 42 |   copyPublicFolder();
 43 | });
 44 | 
 45 | // Print out errors
 46 | function printErrors(summary, errors) {
 47 |   console.log(chalk.red(summary));
 48 |   console.log();
 49 |   errors.forEach(err => {
 50 |     console.log(err.message || err);
 51 |     console.log();
 52 |   });
 53 | }
 54 | 
 55 | // Create the production build and print the deployment instructions.
 56 | function build(previousFileSizes) {
 57 |   console.log('Creating an optimized production build...');
 58 |   webpack(config).run((err, stats) => {
 59 |     if (err) {
 60 |       printErrors('Failed to compile.', [err]);
 61 |       process.exit(1);
 62 |     }
 63 | 
 64 |     if (stats.compilation.errors.length) {
 65 |       printErrors('Failed to compile.', stats.compilation.errors);
 66 |       process.exit(1);
 67 |     }
 68 | 
 69 |     if (process.env.CI && stats.compilation.warnings.length) {
 70 |      printErrors('Failed to compile. When process.env.CI = true, warnings are treated as failures. Most CI servers set this automatically.', stats.compilation.warnings);
 71 |      process.exit(1);
 72 |    }
 73 | 
 74 |     console.log(chalk.green('Compiled successfully.'));
 75 |     console.log();
 76 | 
 77 |     console.log('File sizes after gzip:');
 78 |     console.log();
 79 |     printFileSizesAfterBuild(stats, previousFileSizes);
 80 |     console.log();
 81 | 
 82 |     var appPackage  = require(paths.appPackageJson);
 83 |     var publicUrl = paths.publicUrl;
 84 |     var publicPath = config.output.publicPath;
 85 |     var publicPathname = url.parse(publicPath).pathname;
 86 |     if (publicUrl && publicUrl.indexOf('.github.io/') !== -1) {
 87 |       // "homepage": "http://user.github.io/project"
 88 |       console.log('The project was built assuming it is hosted at ' + chalk.green(publicPathname) + '.');
 89 |       console.log('You can control this with the ' + chalk.green('homepage') + ' field in your '  + chalk.cyan('package.json') + '.');
 90 |       console.log();
 91 |       console.log('The ' + chalk.cyan('build') + ' folder is ready to be deployed.');
 92 |       console.log('To publish it at ' + chalk.green(publicUrl) + ', run:');
 93 |       // If script deploy has been added to package.json, skip the instructions
 94 |       if (typeof appPackage.scripts.deploy === 'undefined') {
 95 |         console.log();
 96 |         if (useYarn) {
 97 |           console.log('  ' + chalk.cyan('yarn') +  ' add --dev gh-pages');
 98 |         } else {
 99 |           console.log('  ' + chalk.cyan('npm') +  ' install --save-dev gh-pages');
100 |         }
101 |         console.log();
102 |         console.log('Add the following script in your ' + chalk.cyan('package.json') + '.');
103 |         console.log();
104 |         console.log('    ' + chalk.dim('// ...'));
105 |         console.log('    ' + chalk.yellow('"scripts"') + ': {');
106 |         console.log('      ' + chalk.dim('// ...'));
107 |         console.log('      ' + chalk.yellow('"predeploy"') + ': ' + chalk.yellow('"npm run build",'));
108 |         console.log('      ' + chalk.yellow('"deploy"') + ': ' + chalk.yellow('"gh-pages -d build"'));
109 |         console.log('    }');
110 |         console.log();
111 |         console.log('Then run:');
112 |       }
113 |       console.log();
114 |       console.log('  ' + chalk.cyan(useYarn ? 'yarn' : 'npm') +  ' run deploy');
115 |       console.log();
116 |     } else if (publicPath !== '/') {
117 |       // "homepage": "http://mywebsite.com/project"
118 |       console.log('The project was built assuming it is hosted at ' + chalk.green(publicPath) + '.');
119 |       console.log('You can control this with the ' + chalk.green('homepage') + ' field in your '  + chalk.cyan('package.json') + '.');
120 |       console.log();
121 |       console.log('The ' + chalk.cyan('build') + ' folder is ready to be deployed.');
122 |       console.log();
123 |     } else {
124 |       if (publicUrl) {
125 |         // "homepage": "http://mywebsite.com"
126 |         console.log('The project was built assuming it is hosted at ' + chalk.green(publicUrl) +  '.');
127 |         console.log('You can control this with the ' + chalk.green('homepage') + ' field in your '  + chalk.cyan('package.json') + '.');
128 |         console.log();
129 |       } else {
130 |         // no homepage
131 |         console.log('The project was built assuming it is hosted at the server root.');
132 |         console.log('To override this, specify the ' + chalk.green('homepage') + ' in your '  + chalk.cyan('package.json') + '.');
133 |         console.log('For example, add this to build it for GitHub Pages:')
134 |         console.log();
135 |         console.log('  ' + chalk.green('"homepage"') + chalk.cyan(': ') + chalk.green('"http://myname.github.io/myapp"') + chalk.cyan(','));
136 |         console.log();
137 |       }
138 |       var build = path.relative(process.cwd(), paths.appBuild);
139 |       console.log('The ' + chalk.cyan(build) + ' folder is ready to be deployed.');
140 |       console.log('You may serve it with a static server:');
141 |       console.log();
142 |       if (useYarn) {
143 |         console.log(`  ${chalk.cyan('yarn')} global add serve`);
144 |       } else {
145 |         console.log(`  ${chalk.cyan('npm')} install -g serve`);
146 |       }
147 |       console.log(`  ${chalk.cyan('serve')} -s build`);
148 |       console.log();
149 |     }
150 |   });
151 | }
152 | 
153 | function copyPublicFolder() {
154 |   fs.copySync(paths.appPublic, paths.appBuild, {
155 |     dereference: true,
156 |     filter: file => file !== paths.appHtml
157 |   });
158 | }
159 | 


--------------------------------------------------------------------------------
/config/webpack.config.dev.js:
--------------------------------------------------------------------------------
  1 | 'use strict';
  2 | 
  3 | var autoprefixer = require('autoprefixer');
  4 | var webpack = require('webpack');
  5 | var HtmlWebpackPlugin = require('html-webpack-plugin');
  6 | var CaseSensitivePathsPlugin = require('case-sensitive-paths-webpack-plugin');
  7 | var InterpolateHtmlPlugin = require('react-dev-utils/InterpolateHtmlPlugin');
  8 | var WatchMissingNodeModulesPlugin = require('react-dev-utils/WatchMissingNodeModulesPlugin');
  9 | var getClientEnvironment = require('./env');
 10 | var paths = require('./paths');
 11 | 
 12 | 
 13 | 
 14 | // Webpack uses `publicPath` to determine where the app is being served from.
 15 | // In development, we always serve from the root. This makes config easier.
 16 | var publicPath = '/';
 17 | // `publicUrl` is just like `publicPath`, but we will provide it to our app
 18 | // as %PUBLIC_URL% in `index.html` and `process.env.PUBLIC_URL` in JavaScript.
 19 | // Omit trailing slash as %PUBLIC_PATH%/xyz looks better than %PUBLIC_PATH%xyz.
 20 | var publicUrl = '';
 21 | // Get environment variables to inject into our app.
 22 | var env = getClientEnvironment(publicUrl);
 23 | 
 24 | // This is the development configuration.
 25 | // It is focused on developer experience and fast rebuilds.
 26 | // The production configuration is different and lives in a separate file.
 27 | module.exports = {
 28 |   // You may want 'eval' instead if you prefer to see the compiled output in DevTools.
 29 |   // See the discussion in https://github.com/facebookincubator/create-react-app/issues/343.
 30 |   devtool: 'cheap-module-source-map',
 31 |   // These are the "entry points" to our application.
 32 |   // This means they will be the "root" imports that are included in JS bundle.
 33 |   // The first two entry points enable "hot" CSS and auto-refreshes for JS.
 34 |   entry: [
 35 |     // Include an alternative client for WebpackDevServer. A client's job is to
 36 |     // connect to WebpackDevServer by a socket and get notified about changes.
 37 |     // When you save a file, the client will either apply hot updates (in case
 38 |     // of CSS changes), or refresh the page (in case of JS changes). When you
 39 |     // make a syntax error, this client will display a syntax error overlay.
 40 |     // Note: instead of the default WebpackDevServer client, we use a custom one
 41 |     // to bring better experience for Create React App users. You can replace
 42 |     // the line below with these two lines if you prefer the stock client:
 43 |     // require.resolve('webpack-dev-server/client') + '?/',
 44 |     // require.resolve('webpack/hot/dev-server'),
 45 |     require.resolve('react-dev-utils/webpackHotDevClient'),
 46 |     // We ship a few polyfills by default:
 47 |     require.resolve('./polyfills'),
 48 |     // Finally, this is your app's code:
 49 |     paths.appIndexJs
 50 |     // We include the app code last so that if there is a runtime error during
 51 |     // initialization, it doesn't blow up the WebpackDevServer client, and
 52 |     // changing JS code would still trigger a refresh.
 53 |   ],
 54 |   output: {
 55 |     // Next line is not used in dev but WebpackDevServer crashes without it:
 56 |     path: paths.appBuild,
 57 |     // Add /* filename */ comments to generated require()s in the output.
 58 |     pathinfo: true,
 59 |     // This does not produce a real file. It's just the virtual path that is
 60 |     // served by WebpackDevServer in development. This is the JS bundle
 61 |     // containing code from all our entry points, and the Webpack runtime.
 62 |     filename: 'static/js/bundle.js',
 63 |     // This is the URL that app is served from. We use "/" in development.
 64 |     publicPath: publicPath
 65 |   },
 66 |   resolve: {
 67 |     // This allows you to set a fallback for where Webpack should look for modules.
 68 |     // We read `NODE_PATH` environment variable in `paths.js` and pass paths here.
 69 |     // We use `fallback` instead of `root` because we want `node_modules` to "win"
 70 |     // if there any conflicts. This matches Node resolution mechanism.
 71 |     // https://github.com/facebookincubator/create-react-app/issues/253
 72 |     fallback: paths.nodePaths,
 73 |     // These are the reasonable defaults supported by the Node ecosystem.
 74 |     // We also include JSX as a common component filename extension to support
 75 |     // some tools, although we do not recommend using it, see:
 76 |     // https://github.com/facebookincubator/create-react-app/issues/290
 77 |     extensions: ['.js', '.json', '.jsx', ''],
 78 |     alias: {
 79 |       // Support React Native Web
 80 |       // https://www.smashingmagazine.com/2016/08/a-glimpse-into-the-future-with-react-native-for-web/
 81 |       'react-native': 'react-native-web'
 82 |     }
 83 |   },
 84 | 
 85 |   module: {
 86 |     // First, run the linter.
 87 |     // It's important to do this before Babel processes the JS.
 88 |     preLoaders: [
 89 |       {
 90 |         test: /\.(js|jsx)$/,
 91 |         loader: 'eslint',
 92 |         include: paths.appSrc,
 93 |       }
 94 |     ],
 95 |     loaders: [
 96 |       // ** ADDING/UPDATING LOADERS **
 97 |       // The "url" loader handles all assets unless explicitly excluded.
 98 |       // The `exclude` list *must* be updated with every change to loader extensions.
 99 |       // When adding a new loader, you must add its `test`
100 |       // as a new entry in the `exclude` list for "url" loader.
101 | 
102 |       // "url" loader embeds assets smaller than specified size as data URLs to avoid requests.
103 |       // Otherwise, it acts like the "file" loader.
104 |       {
105 |         exclude: [
106 |           /\.html$/,
107 |           // We have to write /\.(js|jsx)(\?.*)?$/ rather than just /\.(js|jsx)$/
108 |           // because you might change the hot reloading server from the custom one
109 |           // to Webpack's built-in webpack-dev-server/client?/, which would not
110 |           // get properly excluded by /\.(js|jsx)$/ because of the query string.
111 |           // Webpack 2 fixes this, but for now we include this hack.
112 |           // https://github.com/facebookincubator/create-react-app/issues/1713
113 |           /\.(js|jsx)(\?.*)?$/,
114 |           /\.css$/,
115 |           /\.json$/,
116 |           /\.svg$/
117 |         ],
118 |         loader: 'url',
119 |         query: {
120 |           limit: 10000,
121 |           name: 'static/media/[name].[hash:8].[ext]'
122 |         }
123 |       },
124 |       // Process JS with Babel.
125 |       {
126 |         test: /\.(js|jsx)$/,
127 |         include: paths.appSrc,
128 |         loader: 'babel',
129 |         query: {
130 | 
131 |           // This is a feature of `babel-loader` for webpack (not Babel itself).
132 |           // It enables caching results in ./node_modules/.cache/babel-loader/
133 |           // directory for faster rebuilds.
134 |           cacheDirectory: false
135 |         }
136 |       },
137 |       // "postcss" loader applies autoprefixer to our CSS.
138 |       // "css" loader resolves paths in CSS and adds assets as dependencies.
139 |       // "style" loader turns CSS into JS modules that inject <style> tags.
140 |       // In production, we use a plugin to extract that CSS to a file, but
141 |       // in development "style" loader enables hot editing of CSS.
142 |       {
143 |         test: /\.css$/,
144 |         loader: 'style!css?importLoaders=1!postcss'
145 |       },
146 |       // JSON is not enabled by default in Webpack but both Node and Browserify
147 |       // allow it implicitly so we also enable it.
148 |       {
149 |         test: /\.json$/,
150 |         loader: 'json'
151 |       },
152 |       // "file" loader for svg
153 |       {
154 |         test: /\.svg$/,
155 |         loader: 'file',
156 |         query: {
157 |           name: 'static/media/[name].[hash:8].[ext]'
158 |         }
159 |       }
160 |       // ** STOP ** Are you adding a new loader?
161 |       // Remember to add the new extension(s) to the "url" loader exclusion list.
162 |     ]
163 |   },
164 | 
165 |   // We use PostCSS for autoprefixing only.
166 |   postcss: function() {
167 |     return [
168 |       autoprefixer({
169 |         browsers: [
170 |           '>1%',
171 |           'last 4 versions',
172 |           'Firefox ESR',
173 |           'not ie < 9', // React doesn't support IE8 anyway
174 |         ]
175 |       }),
176 |     ];
177 |   },
178 |   plugins: [
179 |     // Makes some environment variables available in index.html.
180 |     // The public URL is available as %PUBLIC_URL% in index.html, e.g.:
181 |     // <link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">
182 |     // In development, this will be an empty string.
183 |     new InterpolateHtmlPlugin(env.raw),
184 |     // Generates an `index.html` file with the <script> injected.
185 |     new HtmlWebpackPlugin({
186 |       inject: true,
187 |       template: paths.appHtml,
188 |     }),
189 |     // Makes some environment variables available to the JS code, for example:
190 |     // if (process.env.NODE_ENV === 'development') { ... }. See `./env.js`.
191 |     new webpack.DefinePlugin(env.stringified),
192 |     // This is necessary to emit hot updates (currently CSS only):
193 |     new webpack.HotModuleReplacementPlugin(),
194 |     // Watcher doesn't work well if you mistype casing in a path so we use
195 |     // a plugin that prints an error when you attempt to do this.
196 |     // See https://github.com/facebookincubator/create-react-app/issues/240
197 |     new CaseSensitivePathsPlugin(),
198 |     // If you require a missing module and then `npm install` it, you still have
199 |     // to restart the development server for Webpack to discover it. This plugin
200 |     // makes the discovery automatic so you don't have to restart.
201 |     // See https://github.com/facebookincubator/create-react-app/issues/186
202 |     new WatchMissingNodeModulesPlugin(paths.appNodeModules)
203 |   ],
204 |   // Some libraries import Node modules but don't use them in the browser.
205 |   // Tell Webpack to provide empty mocks for them so importing them works.
206 |   node: {
207 |     fs: 'empty',
208 |     net: 'empty',
209 |     tls: 'empty'
210 |   }
211 | };
212 | 


--------------------------------------------------------------------------------
/config/webpack.config.prod.js:
--------------------------------------------------------------------------------
  1 | 'use strict';
  2 | 
  3 | var autoprefixer = require('autoprefixer');
  4 | var webpack = require('webpack');
  5 | var HtmlWebpackPlugin = require('html-webpack-plugin');
  6 | var ExtractTextPlugin = require('extract-text-webpack-plugin');
  7 | var ManifestPlugin = require('webpack-manifest-plugin');
  8 | var InterpolateHtmlPlugin = require('react-dev-utils/InterpolateHtmlPlugin');
  9 | var paths = require('./paths');
 10 | var getClientEnvironment = require('./env');
 11 | 
 12 | 
 13 | 
 14 | // Webpack uses `publicPath` to determine where the app is being served from.
 15 | // It requires a trailing slash, or the file assets will get an incorrect path.
 16 | var publicPath = paths.servedPath;
 17 | // Some apps do not use client-side routing with pushState.
 18 | // For these, "homepage" can be set to "." to enable relative asset paths.
 19 | var shouldUseRelativeAssetPaths = publicPath === './';
 20 | // `publicUrl` is just like `publicPath`, but we will provide it to our app
 21 | // as %PUBLIC_URL% in `index.html` and `process.env.PUBLIC_URL` in JavaScript.
 22 | // Omit trailing slash as %PUBLIC_URL%/xyz looks better than %PUBLIC_URL%xyz.
 23 | var publicUrl = publicPath.slice(0, -1);
 24 | // Get environment variables to inject into our app.
 25 | var env = getClientEnvironment(publicUrl);
 26 | 
 27 | // Assert this just to be safe.
 28 | // Development builds of React are slow and not intended for production.
 29 | if (env.stringified['process.env'].NODE_ENV !== '"production"') {
 30 |   throw new Error('Production builds must have NODE_ENV=production.');
 31 | }
 32 | 
 33 | // Note: defined here because it will be used more than once.
 34 | const cssFilename = 'static/css/[name].[contenthash:8].css';
 35 | 
 36 | // ExtractTextPlugin expects the build output to be flat.
 37 | // (See https://github.com/webpack-contrib/extract-text-webpack-plugin/issues/27)
 38 | // However, our output is structured with css, js and media folders.
 39 | // To have this structure working with relative paths, we have to use custom options.
 40 | const extractTextPluginOptions = shouldUseRelativeAssetPaths
 41 |   // Making sure that the publicPath goes back to to build folder.
 42 |   ? { publicPath: Array(cssFilename.split('/').length).join('../') }
 43 |   : undefined;
 44 | 
 45 | // This is the production configuration.
 46 | // It compiles slowly and is focused on producing a fast and minimal bundle.
 47 | // The development configuration is different and lives in a separate file.
 48 | module.exports = {
 49 |   // Don't attempt to continue if there are any errors.
 50 |   bail: true,
 51 |   // We generate sourcemaps in production. This is slow but gives good results.
 52 |   // You can exclude the *.map files from the build during deployment.
 53 |   devtool: 'source-map',
 54 |   // In production, we only want to load the polyfills and the app code.
 55 |   entry: [
 56 |     require.resolve('./polyfills'),
 57 |     paths.appIndexJs
 58 |   ],
 59 |   output: {
 60 |     // The build folder.
 61 |     path: paths.appBuild,
 62 |     // Generated JS file names (with nested folders).
 63 |     // There will be one main bundle, and one file per asynchronous chunk.
 64 |     // We don't currently advertise code splitting but Webpack supports it.
 65 |     filename: 'static/js/[name].[chunkhash:8].js',
 66 |     chunkFilename: 'static/js/[name].[chunkhash:8].chunk.js',
 67 |     // We inferred the "public path" (such as / or /my-project) from homepage.
 68 |     publicPath: publicPath
 69 |   },
 70 |   resolve: {
 71 |     // This allows you to set a fallback for where Webpack should look for modules.
 72 |     // We read `NODE_PATH` environment variable in `paths.js` and pass paths here.
 73 |     // We use `fallback` instead of `root` because we want `node_modules` to "win"
 74 |     // if there any conflicts. This matches Node resolution mechanism.
 75 |     // https://github.com/facebookincubator/create-react-app/issues/253
 76 |     fallback: paths.nodePaths,
 77 |     // These are the reasonable defaults supported by the Node ecosystem.
 78 |     // We also include JSX as a common component filename extension to support
 79 |     // some tools, although we do not recommend using it, see:
 80 |     // https://github.com/facebookincubator/create-react-app/issues/290
 81 |     extensions: ['.js', '.json', '.jsx', ''],
 82 |     alias: {
 83 |       // Support React Native Web
 84 |       // https://www.smashingmagazine.com/2016/08/a-glimpse-into-the-future-with-react-native-for-web/
 85 |       'react-native': 'react-native-web'
 86 |     }
 87 |   },
 88 |   
 89 |   module: {
 90 |     // First, run the linter.
 91 |     // It's important to do this before Babel processes the JS.
 92 |     preLoaders: [
 93 |       {
 94 |         test: /\.(js|jsx)$/,
 95 |         loader: 'eslint',
 96 |         include: paths.appSrc
 97 |       }
 98 |     ],
 99 |     loaders: [
100 |       // ** ADDING/UPDATING LOADERS **
101 |       // The "url" loader handles all assets unless explicitly excluded.
102 |       // The `exclude` list *must* be updated with every change to loader extensions.
103 |       // When adding a new loader, you must add its `test`
104 |       // as a new entry in the `exclude` list in the "url" loader.
105 | 
106 |       // "url" loader embeds assets smaller than specified size as data URLs to avoid requests.
107 |       // Otherwise, it acts like the "file" loader.
108 |       {
109 |         exclude: [
110 |           /\.html$/,
111 |           /\.(js|jsx)$/,
112 |           /\.css$/,
113 |           /\.json$/,
114 |           /\.svg$/
115 |         ],
116 |         loader: 'url',
117 |         query: {
118 |           limit: 10000,
119 |           name: 'static/media/[name].[hash:8].[ext]'
120 |         }
121 |       },
122 |       // Process JS with Babel.
123 |       {
124 |         test: /\.(js|jsx)$/,
125 |         include: paths.appSrc,
126 |         loader: 'babel',
127 |         
128 |       },
129 |       // The notation here is somewhat confusing.
130 |       // "postcss" loader applies autoprefixer to our CSS.
131 |       // "css" loader resolves paths in CSS and adds assets as dependencies.
132 |       // "style" loader normally turns CSS into JS modules injecting <style>,
133 |       // but unlike in development configuration, we do something different.
134 |       // `ExtractTextPlugin` first applies the "postcss" and "css" loaders
135 |       // (second argument), then grabs the result CSS and puts it into a
136 |       // separate file in our build process. This way we actually ship
137 |       // a single CSS file in production instead of JS code injecting <style>
138 |       // tags. If you use code splitting, however, any async bundles will still
139 |       // use the "style" loader inside the async code so CSS from them won't be
140 |       // in the main CSS file.
141 |       {
142 |         test: /\.css$/,
143 |         loader: ExtractTextPlugin.extract(
144 |           'style',
145 |           'css?importLoaders=1!postcss',
146 |           extractTextPluginOptions
147 |         )
148 |         // Note: this won't work without `new ExtractTextPlugin()` in `plugins`.
149 |       },
150 |       // JSON is not enabled by default in Webpack but both Node and Browserify
151 |       // allow it implicitly so we also enable it.
152 |       {
153 |         test: /\.json$/,
154 |         loader: 'json'
155 |       },
156 |       // "file" loader for svg
157 |       {
158 |         test: /\.svg$/,
159 |         loader: 'file',
160 |         query: {
161 |           name: 'static/media/[name].[hash:8].[ext]'
162 |         }
163 |       }
164 |       // ** STOP ** Are you adding a new loader?
165 |       // Remember to add the new extension(s) to the "url" loader exclusion list.
166 |     ]
167 |   },
168 |   
169 |   // We use PostCSS for autoprefixing only.
170 |   postcss: function() {
171 |     return [
172 |       autoprefixer({
173 |         browsers: [
174 |           '>1%',
175 |           'last 4 versions',
176 |           'Firefox ESR',
177 |           'not ie < 9', // React doesn't support IE8 anyway
178 |         ]
179 |       }),
180 |     ];
181 |   },
182 |   plugins: [
183 |     // Makes some environment variables available in index.html.
184 |     // The public URL is available as %PUBLIC_URL% in index.html, e.g.:
185 |     // <link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">
186 |     // In production, it will be an empty string unless you specify "homepage"
187 |     // in `package.json`, in which case it will be the pathname of that URL.
188 |     new InterpolateHtmlPlugin(env.raw),
189 |     // Generates an `index.html` file with the <script> injected.
190 |     new HtmlWebpackPlugin({
191 |       inject: true,
192 |       template: paths.appHtml,
193 |       minify: {
194 |         removeComments: true,
195 |         collapseWhitespace: true,
196 |         removeRedundantAttributes: true,
197 |         useShortDoctype: true,
198 |         removeEmptyAttributes: true,
199 |         removeStyleLinkTypeAttributes: true,
200 |         keepClosingSlash: true,
201 |         minifyJS: true,
202 |         minifyCSS: true,
203 |         minifyURLs: true
204 |       }
205 |     }),
206 |     // Makes some environment variables available to the JS code, for example:
207 |     // if (process.env.NODE_ENV === 'production') { ... }. See `./env.js`.
208 |     // It is absolutely essential that NODE_ENV was set to production here.
209 |     // Otherwise React will be compiled in the very slow development mode.
210 |     new webpack.DefinePlugin(env.stringified),
211 |     // This helps ensure the builds are consistent if source hasn't changed:
212 |     new webpack.optimize.OccurrenceOrderPlugin(),
213 |     // Try to dedupe duplicated modules, if any:
214 |     new webpack.optimize.DedupePlugin(),
215 |     // Minify the code.
216 |     new webpack.optimize.UglifyJsPlugin({
217 |       compress: {
218 |         screw_ie8: true, // React doesn't support IE8
219 |         warnings: false
220 |       },
221 |       mangle: {
222 |         screw_ie8: true
223 |       },
224 |       output: {
225 |         comments: false,
226 |         screw_ie8: true
227 |       }
228 |     }),
229 |     // Note: this won't work without ExtractTextPlugin.extract(..) in `loaders`.
230 |     new ExtractTextPlugin(cssFilename),
231 |     // Generate a manifest file which contains a mapping of all asset filenames
232 |     // to their corresponding output file so that tools can pick it up without
233 |     // having to parse `index.html`.
234 |     new ManifestPlugin({
235 |       fileName: 'asset-manifest.json'
236 |     })
237 |   ],
238 |   // Some libraries import Node modules but don't use them in the browser.
239 |   // Tell Webpack to provide empty mocks for them so importing them works.
240 |   node: {
241 |     fs: 'empty',
242 |     net: 'empty',
243 |     tls: 'empty'
244 |   }
245 | };
246 | 


--------------------------------------------------------------------------------
/scripts/start.js:
--------------------------------------------------------------------------------
  1 | 'use strict';
  2 | 
  3 | process.env.NODE_ENV = 'development';
  4 | 
  5 | // Load environment variables from .env file. Suppress warnings using silent
  6 | // if this file is missing. dotenv will never modify any environment variables
  7 | // that have already been set.
  8 | // https://github.com/motdotla/dotenv
  9 | require('dotenv').config({silent: true});
 10 | 
 11 | var chalk = require('chalk');
 12 | var webpack = require('webpack');
 13 | var WebpackDevServer = require('webpack-dev-server');
 14 | var historyApiFallback = require('connect-history-api-fallback');
 15 | var httpProxyMiddleware = require('http-proxy-middleware');
 16 | var detect = require('detect-port');
 17 | var clearConsole = require('react-dev-utils/clearConsole');
 18 | var checkRequiredFiles = require('react-dev-utils/checkRequiredFiles');
 19 | var formatWebpackMessages = require('react-dev-utils/formatWebpackMessages');
 20 | var getProcessForPort = require('react-dev-utils/getProcessForPort');
 21 | var openBrowser = require('react-dev-utils/openBrowser');
 22 | var prompt = require('react-dev-utils/prompt');
 23 | var fs = require('fs');
 24 | var config = require('../config/webpack.config.dev');
 25 | var paths = require('../config/paths');
 26 | 
 27 | var useYarn = fs.existsSync(paths.yarnLockFile);
 28 | var cli = useYarn ? 'yarn' : 'npm';
 29 | var isInteractive = process.stdout.isTTY;
 30 | 
 31 | // Warn and crash if required files are missing
 32 | if (!checkRequiredFiles([paths.appHtml, paths.appIndexJs])) {
 33 |   process.exit(1);
 34 | }
 35 | 
 36 | // Tools like Cloud9 rely on this.
 37 | var DEFAULT_PORT = parseInt(process.env.PORT, 10) || 3000;
 38 | var compiler;
 39 | var handleCompile;
 40 | 
 41 | // You can safely remove this after ejecting.
 42 | // We only use this block for testing of Create React App itself:
 43 | var isSmokeTest = process.argv.some(arg => arg.indexOf('--smoke-test') > -1);
 44 | if (isSmokeTest) {
 45 |   handleCompile = function (err, stats) {
 46 |     if (err || stats.hasErrors() || stats.hasWarnings()) {
 47 |       process.exit(1);
 48 |     } else {
 49 |       process.exit(0);
 50 |     }
 51 |   };
 52 | }
 53 | 
 54 | function setupCompiler(host, port, protocol) {
 55 |   // "Compiler" is a low-level interface to Webpack.
 56 |   // It lets us listen to some events and provide our own custom messages.
 57 |   compiler = webpack(config, handleCompile);
 58 | 
 59 |   // "invalid" event fires when you have changed a file, and Webpack is
 60 |   // recompiling a bundle. WebpackDevServer takes care to pause serving the
 61 |   // bundle, so if you refresh, it'll wait instead of serving the old one.
 62 |   // "invalid" is short for "bundle invalidated", it doesn't imply any errors.
 63 |   compiler.plugin('invalid', function() {
 64 |     if (isInteractive) {
 65 |       //clearConsole();
 66 |     }
 67 |     console.log('Compiling...');
 68 |   });
 69 | 
 70 |   var isFirstCompile = true;
 71 | 
 72 |   // "done" event fires when Webpack has finished recompiling the bundle.
 73 |   // Whether or not you have warnings or errors, you will get this event.
 74 |   compiler.plugin('done', function(stats) {
 75 |     if (isInteractive) {
 76 |       //clearConsole();
 77 |     }
 78 | 
 79 |     // We have switched off the default Webpack output in WebpackDevServer
 80 |     // options so we are going to "massage" the warnings and errors and present
 81 |     // them in a readable focused way.
 82 |     var messages = formatWebpackMessages(stats.toJson({}, true));
 83 |     var isSuccessful = !messages.errors.length && !messages.warnings.length;
 84 |     var showInstructions = isSuccessful && (isInteractive || isFirstCompile);
 85 | 
 86 |     if (isSuccessful) {
 87 |       console.log(chalk.green('Compiled successfully!'));
 88 |     }
 89 | 
 90 |     if (showInstructions) {
 91 |       console.log();
 92 |       console.log('The app is running at:');
 93 |       console.log();
 94 |       console.log('  ' + chalk.cyan(protocol + '://' + host + ':' + port + '/'));
 95 |       console.log();
 96 |       console.log('Note that the development build is not optimized.');
 97 |       console.log('To create a production build, use ' + chalk.cyan(cli + ' run build') + '.');
 98 |       console.log();
 99 |       isFirstCompile = false;
100 |     }
101 | 
102 |     // If errors exist, only show errors.
103 |     if (messages.errors.length) {
104 |       console.log(chalk.red('Failed to compile.'));
105 |       console.log();
106 |       messages.errors.forEach(message => {
107 |         console.log(message);
108 |         console.log();
109 |       });
110 |       return;
111 |     }
112 | 
113 |     // Show warnings if no errors were found.
114 |     if (messages.warnings.length) {
115 |       console.log(chalk.yellow('Compiled with warnings.'));
116 |       console.log();
117 |       messages.warnings.forEach(message => {
118 |         console.log(message);
119 |         console.log();
120 |       });
121 |       // Teach some ESLint tricks.
122 |       console.log('You may use special comments to disable some warnings.');
123 |       console.log('Use ' + chalk.yellow('// eslint-disable-next-line') + ' to ignore the next line.');
124 |       console.log('Use ' + chalk.yellow('/* eslint-disable */') + ' to ignore all warnings in a file.');
125 |     }
126 |   });
127 | }
128 | 
129 | // We need to provide a custom onError function for httpProxyMiddleware.
130 | // It allows us to log custom error messages on the console.
131 | function onProxyError(proxy) {
132 |   return function(err, req, res){
133 |     var host = req.headers && req.headers.host;
134 |     console.log(
135 |       chalk.red('Proxy error:') + ' Could not proxy request ' + chalk.cyan(req.url) +
136 |       ' from ' + chalk.cyan(host) + ' to ' + chalk.cyan(proxy) + '.'
137 |     );
138 |     console.log(
139 |       'See https://nodejs.org/api/errors.html#errors_common_system_errors for more information (' +
140 |       chalk.cyan(err.code) + ').'
141 |     );
142 |     console.log();
143 | 
144 |     // And immediately send the proper error response to the client.
145 |     // Otherwise, the request will eventually timeout with ERR_EMPTY_RESPONSE on the client side.
146 |     if (res.writeHead && !res.headersSent) {
147 |         res.writeHead(500);
148 |     }
149 |     res.end('Proxy error: Could not proxy request ' + req.url + ' from ' +
150 |       host + ' to ' + proxy + ' (' + err.code + ').'
151 |     );
152 |   }
153 | }
154 | 
155 | function addMiddleware(devServer) {
156 |   // `proxy` lets you to specify a fallback server during development.
157 |   // Every unrecognized request will be forwarded to it.
158 |   var proxy = require(paths.appPackageJson).proxy;
159 |   devServer.use(historyApiFallback({
160 |     // Paths with dots should still use the history fallback.
161 |     // See https://github.com/facebookincubator/create-react-app/issues/387.
162 |     disableDotRule: true,
163 |     // For single page apps, we generally want to fallback to /index.html.
164 |     // However we also want to respect `proxy` for API calls.
165 |     // So if `proxy` is specified, we need to decide which fallback to use.
166 |     // We use a heuristic: if request `accept`s text/html, we pick /index.html.
167 |     // Modern browsers include text/html into `accept` header when navigating.
168 |     // However API calls like `fetch()` won’t generally accept text/html.
169 |     // If this heuristic doesn’t work well for you, don’t use `proxy`.
170 |     htmlAcceptHeaders: proxy ?
171 |       ['text/html'] :
172 |       ['text/html', '*/*']
173 |   }));
174 |   if (proxy) {
175 |     if (typeof proxy !== 'string') {
176 |       console.log(chalk.red('When specified, "proxy" in package.json must be a string.'));
177 |       console.log(chalk.red('Instead, the type of "proxy" was "' + typeof proxy + '".'));
178 |       console.log(chalk.red('Either remove "proxy" from package.json, or make it a string.'));
179 |       process.exit(1);
180 |     }
181 | 
182 |     // Otherwise, if proxy is specified, we will let it handle any request.
183 |     // There are a few exceptions which we won't send to the proxy:
184 |     // - /index.html (served as HTML5 history API fallback)
185 |     // - /*.hot-update.json (WebpackDevServer uses this too for hot reloading)
186 |     // - /sockjs-node/* (WebpackDevServer uses this for hot reloading)
187 |     // Tip: use https://jex.im/regulex/ to visualize the regex
188 |     var mayProxy = /^(?!\/(index\.html$|.*\.hot-update\.json$|sockjs-node\/)).*$/;
189 | 
190 |     // Pass the scope regex both to Express and to the middleware for proxying
191 |     // of both HTTP and WebSockets to work without false positives.
192 |     var hpm = httpProxyMiddleware(pathname => mayProxy.test(pathname), {
193 |       target: proxy,
194 |       logLevel: 'silent',
195 |       onProxyReq: function(proxyReq) {
196 |         // Browers may send Origin headers even with same-origin
197 |         // requests. To prevent CORS issues, we have to change
198 |         // the Origin to match the target URL.
199 |         if (proxyReq.getHeader('origin')) {
200 |           proxyReq.setHeader('origin', proxy);
201 |         }
202 |       },
203 |       onError: onProxyError(proxy),
204 |       secure: false,
205 |       changeOrigin: true,
206 |       ws: true,
207 |       xfwd: true
208 |     });
209 |     devServer.use(mayProxy, hpm);
210 | 
211 |     // Listen for the websocket 'upgrade' event and upgrade the connection.
212 |     // If this is not done, httpProxyMiddleware will not try to upgrade until
213 |     // an initial plain HTTP request is made.
214 |     devServer.listeningApp.on('upgrade', hpm.upgrade);
215 |   }
216 | 
217 |   // Finally, by now we have certainly resolved the URL.
218 |   // It may be /index.html, so let the dev server try serving it again.
219 |   devServer.use(devServer.middleware);
220 | }
221 | 
222 | function runDevServer(host, port, protocol) {
223 |   var devServer = new WebpackDevServer(compiler, {
224 |     // Enable gzip compression of generated files.
225 |     compress: true,
226 |     // Silence WebpackDevServer's own logs since they're generally not useful.
227 |     // It will still show compile warnings and errors with this setting.
228 |     clientLogLevel: 'none',
229 |     // By default WebpackDevServer serves physical files from current directory
230 |     // in addition to all the virtual build products that it serves from memory.
231 |     // This is confusing because those files won’t automatically be available in
232 |     // production build folder unless we copy them. However, copying the whole
233 |     // project directory is dangerous because we may expose sensitive files.
234 |     // Instead, we establish a convention that only files in `public` directory
235 |     // get served. Our build script will copy `public` into the `build` folder.
236 |     // In `index.html`, you can get URL of `public` folder with %PUBLIC_URL%:
237 |     // <link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">
238 |     // In JavaScript code, you can access it with `process.env.PUBLIC_URL`.
239 |     // Note that we only recommend to use `public` folder as an escape hatch
240 |     // for files like `favicon.ico`, `manifest.json`, and libraries that are
241 |     // for some reason broken when imported through Webpack. If you just want to
242 |     // use an image, put it in `src` and `import` it from JavaScript instead.
243 |     contentBase: paths.appPublic,
244 |     // Enable hot reloading server. It will provide /sockjs-node/ endpoint
245 |     // for the WebpackDevServer client so it can learn when the files were
246 |     // updated. The WebpackDevServer client is included as an entry point
247 |     // in the Webpack development configuration. Note that only changes
248 |     // to CSS are currently hot reloaded. JS changes will refresh the browser.
249 |     hot: true,
250 |     // It is important to tell WebpackDevServer to use the same "root" path
251 |     // as we specified in the config. In development, we always serve from /.
252 |     publicPath: config.output.publicPath,
253 |     // WebpackDevServer is noisy by default so we emit custom message instead
254 |     // by listening to the compiler events with `compiler.plugin` calls above.
255 |     quiet: true,
256 |     // Reportedly, this avoids CPU overload on some systems.
257 |     // https://github.com/facebookincubator/create-react-app/issues/293
258 |     watchOptions: {
259 |       ignored: /node_modules/
260 |     },
261 |     // Enable HTTPS if the HTTPS environment variable is set to 'true'
262 |     https: protocol === "https",
263 |     host: host
264 |   });
265 | 
266 |   // Our custom middleware proxies requests to /index.html or a remote API.
267 |   addMiddleware(devServer);
268 | 
269 |   // Launch WebpackDevServer.
270 |   devServer.listen(port, err => {
271 |     if (err) {
272 |       return console.log(err);
273 |     }
274 | 
275 |     if (isInteractive) {
276 |       //clearConsole();
277 |     }
278 |     console.log(chalk.cyan('Starting the development server...'));
279 |     console.log();
280 | 
281 |     //openBrowser(protocol + '://' + host + ':' + port + '/');
282 |   });
283 | }
284 | 
285 | function run(port) {
286 |   var protocol = process.env.HTTPS === 'true' ? "https" : "http";
287 |   var host = process.env.HOST || 'localhost';
288 |   setupCompiler(host, port, protocol);
289 |   runDevServer(host, port, protocol);
290 | }
291 | 
292 | // We attempt to use the default port but if it is busy, we offer the user to
293 | // run on a different port. `detect()` Promise resolves to the next free port.
294 | detect(DEFAULT_PORT).then(port => {
295 |   if (port === DEFAULT_PORT) {
296 |     run(port);
297 |     return;
298 |   }
299 | 
300 |   if (isInteractive) {
301 |     //clearConsole();
302 |     var existingProcess = getProcessForPort(DEFAULT_PORT);
303 |     var question =
304 |       chalk.yellow('Something is already running on port ' + DEFAULT_PORT + '.' +
305 |         ((existingProcess) ? ' Probably:\n  ' + existingProcess : '')) +
306 |         '\n\nWould you like to run the app on another port instead?';
307 | 
308 |     prompt(question, true).then(shouldChangePort => {
309 |       if (shouldChangePort) {
310 |         run(port);
311 |       }
312 |     });
313 |   } else {
314 |     console.log(chalk.red('Something is already running on port ' + DEFAULT_PORT + '.'));
315 |   }
316 | });
317 | 


--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
   1 | This project was bootstrapped with [Create React App](https://github.com/facebookincubator/create-react-app).
   2 | 
   3 | Below you will find some information on how to perform common tasks.<br>
   4 | You can find the most recent version of this guide [here](https://github.com/facebookincubator/create-react-app/blob/master/packages/react-scripts/template/README.md).
   5 | 
   6 | ## Table of Contents
   7 | 
   8 | - [Updating to New Releases](#updating-to-new-releases)
   9 | - [Sending Feedback](#sending-feedback)
  10 | - [Folder Structure](#folder-structure)
  11 | - [Available Scripts](#available-scripts)
  12 |   - [npm start](#npm-start)
  13 |   - [npm test](#npm-test)
  14 |   - [npm run build](#npm-run-build)
  15 |   - [npm run eject](#npm-run-eject)
  16 | - [Supported Language Features and Polyfills](#supported-language-features-and-polyfills)
  17 | - [Syntax Highlighting in the Editor](#syntax-highlighting-in-the-editor)
  18 | - [Displaying Lint Output in the Editor](#displaying-lint-output-in-the-editor)
  19 | - [Debugging in the Editor](#debugging-in-the-editor)
  20 | - [Changing the Page `<title>`](#changing-the-page-title)
  21 | - [Installing a Dependency](#installing-a-dependency)
  22 | - [Importing a Component](#importing-a-component)
  23 | - [Adding a Stylesheet](#adding-a-stylesheet)
  24 | - [Post-Processing CSS](#post-processing-css)
  25 | - [Adding a CSS Preprocessor (Sass, Less etc.)](#adding-a-css-preprocessor-sass-less-etc)
  26 | - [Adding Images and Fonts](#adding-images-and-fonts)
  27 | - [Using the `public` Folder](#using-the-public-folder)
  28 |   - [Changing the HTML](#changing-the-html)
  29 |   - [Adding Assets Outside of the Module System](#adding-assets-outside-of-the-module-system)
  30 |   - [When to Use the `public` Folder](#when-to-use-the-public-folder)
  31 | - [Using Global Variables](#using-global-variables)
  32 | - [Adding Bootstrap](#adding-bootstrap)
  33 |   - [Using a Custom Theme](#using-a-custom-theme)
  34 | - [Adding Flow](#adding-flow)
  35 | - [Adding Custom Environment Variables](#adding-custom-environment-variables)
  36 |   - [Referencing Environment Variables in the HTML](#referencing-environment-variables-in-the-html)
  37 |   - [Adding Temporary Environment Variables In Your Shell](#adding-temporary-environment-variables-in-your-shell)
  38 |   - [Adding Development Environment Variables In `.env`](#adding-development-environment-variables-in-env)
  39 | - [Can I Use Decorators?](#can-i-use-decorators)
  40 | - [Integrating with an API Backend](#integrating-with-an-api-backend)
  41 |   - [Node](#node)
  42 |   - [Ruby on Rails](#ruby-on-rails)
  43 | - [Proxying API Requests in Development](#proxying-api-requests-in-development)
  44 | - [Using HTTPS in Development](#using-https-in-development)
  45 | - [Generating Dynamic `<meta>` Tags on the Server](#generating-dynamic-meta-tags-on-the-server)
  46 | - [Pre-Rendering into Static HTML Files](#pre-rendering-into-static-html-files)
  47 | - [Injecting Data from the Server into the Page](#injecting-data-from-the-server-into-the-page)
  48 | - [Running Tests](#running-tests)
  49 |   - [Filename Conventions](#filename-conventions)
  50 |   - [Command Line Interface](#command-line-interface)
  51 |   - [Version Control Integration](#version-control-integration)
  52 |   - [Writing Tests](#writing-tests)
  53 |   - [Testing Components](#testing-components)
  54 |   - [Using Third Party Assertion Libraries](#using-third-party-assertion-libraries)
  55 |   - [Initializing Test Environment](#initializing-test-environment)
  56 |   - [Focusing and Excluding Tests](#focusing-and-excluding-tests)
  57 |   - [Coverage Reporting](#coverage-reporting)
  58 |   - [Continuous Integration](#continuous-integration)
  59 |   - [Disabling jsdom](#disabling-jsdom)
  60 |   - [Snapshot Testing](#snapshot-testing)
  61 |   - [Editor Integration](#editor-integration)
  62 | - [Developing Components in Isolation](#developing-components-in-isolation)
  63 | - [Making a Progressive Web App](#making-a-progressive-web-app)
  64 | - [Deployment](#deployment)
  65 |   - [Static Server](#static-server)
  66 |   - [Other Solutions](#other-solutions)
  67 |   - [Serving Apps with Client-Side Routing](#serving-apps-with-client-side-routing)
  68 |   - [Building for Relative Paths](#building-for-relative-paths)
  69 |   - [Azure](#azure)
  70 |   - [Firebase](#firebase)
  71 |   - [GitHub Pages](#github-pages)
  72 |   - [Heroku](#heroku)
  73 |   - [Modulus](#modulus)
  74 |   - [Netlify](#netlify)
  75 |   - [Now](#now)
  76 |   - [S3 and CloudFront](#s3-and-cloudfront)
  77 |   - [Surge](#surge)
  78 | - [Advanced Configuration](#advanced-configuration)
  79 | - [Troubleshooting](#troubleshooting)
  80 |   - [`npm start` doesn’t detect changes](#npm-start-doesnt-detect-changes)
  81 |   - [`npm test` hangs on macOS Sierra](#npm-test-hangs-on-macos-sierra)
  82 |   - [`npm run build` silently fails](#npm-run-build-silently-fails)
  83 |   - [`npm run build` fails on Heroku](#npm-run-build-fails-on-heroku)
  84 | - [Something Missing?](#something-missing)
  85 | 
  86 | ## Updating to New Releases
  87 | 
  88 | Create React App is divided into two packages:
  89 | 
  90 | * `create-react-app` is a global command-line utility that you use to create new projects.
  91 | * `react-scripts` is a development dependency in the generated projects (including this one).
  92 | 
  93 | You almost never need to update `create-react-app` itself: it delegates all the setup to `react-scripts`.
  94 | 
  95 | When you run `create-react-app`, it always creates the project with the latest version of `react-scripts` so you’ll get all the new features and improvements in newly created apps automatically.
  96 | 
  97 | To update an existing project to a new version of `react-scripts`, [open the changelog](https://github.com/facebookincubator/create-react-app/blob/master/CHANGELOG.md), find the version you’re currently on (check `package.json` in this folder if you’re not sure), and apply the migration instructions for the newer versions.
  98 | 
  99 | In most cases bumping the `react-scripts` version in `package.json` and running `npm install` in this folder should be enough, but it’s good to consult the [changelog](https://github.com/facebookincubator/create-react-app/blob/master/CHANGELOG.md) for potential breaking changes.
 100 | 
 101 | We commit to keeping the breaking changes minimal so you can upgrade `react-scripts` painlessly.
 102 | 
 103 | ## Sending Feedback
 104 | 
 105 | We are always open to [your feedback](https://github.com/facebookincubator/create-react-app/issues).
 106 | 
 107 | ## Folder Structure
 108 | 
 109 | After creation, your project should look like this:
 110 | 
 111 | ```
 112 | my-app/
 113 |   README.md
 114 |   node_modules/
 115 |   package.json
 116 |   public/
 117 |     index.html
 118 |     favicon.ico
 119 |   src/
 120 |     App.css
 121 |     App.js
 122 |     App.test.js
 123 |     index.css
 124 |     index.js
 125 |     logo.svg
 126 | ```
 127 | 
 128 | For the project to build, **these files must exist with exact filenames**:
 129 | 
 130 | * `public/index.html` is the page template;
 131 | * `src/index.js` is the JavaScript entry point.
 132 | 
 133 | You can delete or rename the other files.
 134 | 
 135 | You may create subdirectories inside `src`. For faster rebuilds, only files inside `src` are processed by Webpack.<br>
 136 | You need to **put any JS and CSS files inside `src`**, or Webpack won’t see them.
 137 | 
 138 | Only files inside `public` can be used from `public/index.html`.<br>
 139 | Read instructions below for using assets from JavaScript and HTML.
 140 | 
 141 | You can, however, create more top-level directories.<br>
 142 | They will not be included in the production build so you can use them for things like documentation.
 143 | 
 144 | ## Available Scripts
 145 | 
 146 | In the project directory, you can run:
 147 | 
 148 | ### `npm start`
 149 | 
 150 | Runs the app in the development mode.<br>
 151 | Open [http://localhost:3000](http://localhost:3000) to view it in the browser.
 152 | 
 153 | The page will reload if you make edits.<br>
 154 | You will also see any lint errors in the console.
 155 | 
 156 | ### `npm test`
 157 | 
 158 | Launches the test runner in the interactive watch mode.<br>
 159 | See the section about [running tests](#running-tests) for more information.
 160 | 
 161 | ### `npm run build`
 162 | 
 163 | Builds the app for production to the `build` folder.<br>
 164 | It correctly bundles React in production mode and optimizes the build for the best performance.
 165 | 
 166 | The build is minified and the filenames include the hashes.<br>
 167 | Your app is ready to be deployed!
 168 | 
 169 | See the section about [deployment](#deployment) for more information.
 170 | 
 171 | ### `npm run eject`
 172 | 
 173 | **Note: this is a one-way operation. Once you `eject`, you can’t go back!**
 174 | 
 175 | If you aren’t satisfied with the build tool and configuration choices, you can `eject` at any time. This command will remove the single build dependency from your project.
 176 | 
 177 | Instead, it will copy all the configuration files and the transitive dependencies (Webpack, Babel, ESLint, etc) right into your project so you have full control over them. All of the commands except `eject` will still work, but they will point to the copied scripts so you can tweak them. At this point you’re on your own.
 178 | 
 179 | You don’t have to ever use `eject`. The curated feature set is suitable for small and middle deployments, and you shouldn’t feel obligated to use this feature. However we understand that this tool wouldn’t be useful if you couldn’t customize it when you are ready for it.
 180 | 
 181 | ## Supported Language Features and Polyfills
 182 | 
 183 | This project supports a superset of the latest JavaScript standard.<br>
 184 | In addition to [ES6](https://github.com/lukehoban/es6features) syntax features, it also supports:
 185 | 
 186 | * [Exponentiation Operator](https://github.com/rwaldron/exponentiation-operator) (ES2016).
 187 | * [Async/await](https://github.com/tc39/ecmascript-asyncawait) (ES2017).
 188 | * [Object Rest/Spread Properties](https://github.com/sebmarkbage/ecmascript-rest-spread) (stage 3 proposal).
 189 | * [Class Fields and Static Properties](https://github.com/tc39/proposal-class-public-fields) (stage 2 proposal).
 190 | * [JSX](https://facebook.github.io/react/docs/introducing-jsx.html) and [Flow](https://flowtype.org/) syntax.
 191 | 
 192 | Learn more about [different proposal stages](https://babeljs.io/docs/plugins/#presets-stage-x-experimental-presets-).
 193 | 
 194 | While we recommend to use experimental proposals with some caution, Facebook heavily uses these features in the product code, so we intend to provide [codemods](https://medium.com/@cpojer/effective-javascript-codemods-5a6686bb46fb) if any of these proposals change in the future.
 195 | 
 196 | Note that **the project only includes a few ES6 [polyfills](https://en.wikipedia.org/wiki/Polyfill)**:
 197 | 
 198 | * [`Object.assign()`](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Object/assign) via [`object-assign`](https://github.com/sindresorhus/object-assign).
 199 | * [`Promise`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise) via [`promise`](https://github.com/then/promise).
 200 | * [`fetch()`](https://developer.mozilla.org/en/docs/Web/API/Fetch_API) via [`whatwg-fetch`](https://github.com/github/fetch).
 201 | 
 202 | If you use any other ES6+ features that need **runtime support** (such as `Array.from()` or `Symbol`), make sure you are including the appropriate polyfills manually, or that the browsers you are targeting already support them.
 203 | 
 204 | ## Syntax Highlighting in the Editor
 205 | 
 206 | To configure the syntax highlighting in your favorite text editor, head to the [relevant Babel documentation page](https://babeljs.io/docs/editors) and follow the instructions. Some of the most popular editors are covered.
 207 | 
 208 | ## Displaying Lint Output in the Editor
 209 | 
 210 | >Note: this feature is available with `react-scripts@0.2.0` and higher.
 211 | 
 212 | Some editors, including Sublime Text, Atom, and Visual Studio Code, provide plugins for ESLint.
 213 | 
 214 | They are not required for linting. You should see the linter output right in your terminal as well as the browser console. However, if you prefer the lint results to appear right in your editor, there are some extra steps you can do.
 215 | 
 216 | You would need to install an ESLint plugin for your editor first.
 217 | 
 218 | >**A note for Atom `linter-eslint` users**
 219 | 
 220 | >If you are using the Atom `linter-eslint` plugin, make sure that **Use global ESLint installation** option is checked:
 221 | 
 222 | ><img src="http://i.imgur.com/yVNNHJM.png" width="300">
 223 | 
 224 | 
 225 | >**For Visual Studio Code users**
 226 | 
 227 | >VS Code ESLint plugin automatically detects Create React App's configuration file. So you do not need to create `eslintrc.json` at the root directory, except when you want to add your own rules. In that case, you should include CRA's config by adding this line:
 228 | 
 229 | >```js
 230 | {
 231 |   // ...
 232 |   "extends": "react-app"
 233 | }
 234 | ```
 235 | 
 236 | Then add this block to the `package.json` file of your project:
 237 | 
 238 | ```js
 239 | {
 240 |   // ...
 241 |   "eslintConfig": {
 242 |     "extends": "react-app"
 243 |   }
 244 | }
 245 | ```
 246 | 
 247 | Finally, you will need to install some packages *globally*:
 248 | 
 249 | ```sh
 250 | npm install -g eslint-config-react-app@0.3.0 eslint@3.8.1 babel-eslint@7.0.0 eslint-plugin-react@6.4.1 eslint-plugin-import@2.0.1 eslint-plugin-jsx-a11y@4.0.0 eslint-plugin-flowtype@2.21.0
 251 | ```
 252 | 
 253 | We recognize that this is suboptimal, but it is currently required due to the way we hide the ESLint dependency. The ESLint team is already [working on a solution to this](https://github.com/eslint/eslint/issues/3458) so this may become unnecessary in a couple of months.
 254 | 
 255 | ## Debugging in the Editor
 256 | 
 257 | **This feature is currently only supported by [Visual Studio Code](https://code.visualstudio.com) editor.**
 258 | 
 259 | Visual Studio Code supports live-editing and debugging out of the box with Create React App. This enables you as a developer to write and debug your React code without leaving the editor, and most importantly it enables you to have a continuous development workflow, where context switching is minimal, as you don’t have to switch between tools.
 260 | 
 261 | You would need to have the latest version of [VS Code](https://code.visualstudio.com) and VS Code [Chrome Debugger Extension](https://marketplace.visualstudio.com/items?itemName=msjsdiag.debugger-for-chrome) installed.
 262 | 
 263 | Then add the block below to your `launch.json` file and put it inside the `.vscode` folder in your app’s root directory.
 264 | 
 265 | ```json
 266 | {
 267 |   "version": "0.2.0",
 268 |   "configurations": [{
 269 |     "name": "Chrome",
 270 |     "type": "chrome",
 271 |     "request": "launch",
 272 |     "url": "http://localhost:3000",
 273 |     "webRoot": "${workspaceRoot}/src",
 274 |     "userDataDir": "${workspaceRoot}/.vscode/chrome",
 275 |     "sourceMapPathOverrides": {
 276 |       "webpack:///src/*": "${webRoot}/*"
 277 |     }
 278 |   }]
 279 | }
 280 | ```
 281 | 
 282 | Start your app by running `npm start`, and start debugging in VS Code by pressing `F5` or by clicking the green debug icon. You can now write code, set breakpoints, make changes to the code, and debug your newly modified code—all from your editor.
 283 | 
 284 | ## Changing the Page `<title>`
 285 | 
 286 | You can find the source HTML file in the `public` folder of the generated project. You may edit the `<title>` tag in it to change the title from “React App” to anything else.
 287 | 
 288 | Note that normally you wouldn’t edit files in the `public` folder very often. For example, [adding a stylesheet](#adding-a-stylesheet) is done without touching the HTML.
 289 | 
 290 | If you need to dynamically update the page title based on the content, you can use the browser [`document.title`](https://developer.mozilla.org/en-US/docs/Web/API/Document/title) API. For more complex scenarios when you want to change the title from React components, you can use [React Helmet](https://github.com/nfl/react-helmet), a third party library.
 291 | 
 292 | If you use a custom server for your app in production and want to modify the title before it gets sent to the browser, you can follow advice in [this section](#generating-dynamic-meta-tags-on-the-server). Alternatively, you can pre-build each page as a static HTML file which then loads the JavaScript bundle, which is covered [here](#pre-rendering-into-static-html-files).
 293 | 
 294 | ## Installing a Dependency
 295 | 
 296 | The generated project includes React and ReactDOM as dependencies. It also includes a set of scripts used by Create React App as a development dependency. You may install other dependencies (for example, React Router) with `npm`:
 297 | 
 298 | ```
 299 | npm install --save <library-name>
 300 | ```
 301 | 
 302 | ## Importing a Component
 303 | 
 304 | This project setup supports ES6 modules thanks to Babel.<br>
 305 | While you can still use `require()` and `module.exports`, we encourage you to use [`import` and `export`](http://exploringjs.com/es6/ch_modules.html) instead.
 306 | 
 307 | For example:
 308 | 
 309 | ### `Button.js`
 310 | 
 311 | ```js
 312 | import React, { Component } from 'react';
 313 | 
 314 | class Button extends Component {
 315 |   render() {
 316 |     // ...
 317 |   }
 318 | }
 319 | 
 320 | export default Button; // Don’t forget to use export default!
 321 | ```
 322 | 
 323 | ### `DangerButton.js`
 324 | 
 325 | 
 326 | ```js
 327 | import React, { Component } from 'react';
 328 | import Button from './Button'; // Import a component from another file
 329 | 
 330 | class DangerButton extends Component {
 331 |   render() {
 332 |     return <Button color="red" />;
 333 |   }
 334 | }
 335 | 
 336 | export default DangerButton;
 337 | ```
 338 | 
 339 | Be aware of the [difference between default and named exports](http://stackoverflow.com/questions/36795819/react-native-es-6-when-should-i-use-curly-braces-for-import/36796281#36796281). It is a common source of mistakes.
 340 | 
 341 | We suggest that you stick to using default imports and exports when a module only exports a single thing (for example, a component). That’s what you get when you use `export default Button` and `import Button from './Button'`.
 342 | 
 343 | Named exports are useful for utility modules that export several functions. A module may have at most one default export and as many named exports as you like.
 344 | 
 345 | Learn more about ES6 modules:
 346 | 
 347 | * [When to use the curly braces?](http://stackoverflow.com/questions/36795819/react-native-es-6-when-should-i-use-curly-braces-for-import/36796281#36796281)
 348 | * [Exploring ES6: Modules](http://exploringjs.com/es6/ch_modules.html)
 349 | * [Understanding ES6: Modules](https://leanpub.com/understandinges6/read#leanpub-auto-encapsulating-code-with-modules)
 350 | 
 351 | ## Adding a Stylesheet
 352 | 
 353 | This project setup uses [Webpack](https://webpack.github.io/) for handling all assets. Webpack offers a custom way of “extending” the concept of `import` beyond JavaScript. To express that a JavaScript file depends on a CSS file, you need to **import the CSS from the JavaScript file**:
 354 | 
 355 | ### `Button.css`
 356 | 
 357 | ```css
 358 | .Button {
 359 |   padding: 20px;
 360 | }
 361 | ```
 362 | 
 363 | ### `Button.js`
 364 | 
 365 | ```js
 366 | import React, { Component } from 'react';
 367 | import './Button.css'; // Tell Webpack that Button.js uses these styles
 368 | 
 369 | class Button extends Component {
 370 |   render() {
 371 |     // You can use them as regular CSS styles
 372 |     return <div className="Button" />;
 373 |   }
 374 | }
 375 | ```
 376 | 
 377 | **This is not required for React** but many people find this feature convenient. You can read about the benefits of this approach [here](https://medium.com/seek-ui-engineering/block-element-modifying-your-javascript-components-d7f99fcab52b). However you should be aware that this makes your code less portable to other build tools and environments than Webpack.
 378 | 
 379 | In development, expressing dependencies this way allows your styles to be reloaded on the fly as you edit them. In production, all CSS files will be concatenated into a single minified `.css` file in the build output.
 380 | 
 381 | If you are concerned about using Webpack-specific semantics, you can put all your CSS right into `src/index.css`. It would still be imported from `src/index.js`, but you could always remove that import if you later migrate to a different build tool.
 382 | 
 383 | ## Post-Processing CSS
 384 | 
 385 | This project setup minifies your CSS and adds vendor prefixes to it automatically through [Autoprefixer](https://github.com/postcss/autoprefixer) so you don’t need to worry about it.
 386 | 
 387 | For example, this:
 388 | 
 389 | ```css
 390 | .App {
 391 |   display: flex;
 392 |   flex-direction: row;
 393 |   align-items: center;
 394 | }
 395 | ```
 396 | 
 397 | becomes this:
 398 | 
 399 | ```css
 400 | .App {
 401 |   display: -webkit-box;
 402 |   display: -ms-flexbox;
 403 |   display: flex;
 404 |   -webkit-box-orient: horizontal;
 405 |   -webkit-box-direction: normal;
 406 |       -ms-flex-direction: row;
 407 |           flex-direction: row;
 408 |   -webkit-box-align: center;
 409 |       -ms-flex-align: center;
 410 |           align-items: center;
 411 | }
 412 | ```
 413 | 
 414 | If you need to disable autoprefixing for some reason, [follow this section](https://github.com/postcss/autoprefixer#disabling).
 415 | 
 416 | ## Adding a CSS Preprocessor (Sass, Less etc.)
 417 | 
 418 | Generally, we recommend that you don’t reuse the same CSS classes across different components. For example, instead of using a `.Button` CSS class in `<AcceptButton>` and `<RejectButton>` components, we recommend creating a `<Button>` component with its own `.Button` styles, that both `<AcceptButton>` and `<RejectButton>` can render (but [not inherit](https://facebook.github.io/react/docs/composition-vs-inheritance.html)).
 419 | 
 420 | Following this rule often makes CSS preprocessors less useful, as features like mixins and nesting are replaced by component composition. You can, however, integrate a CSS preprocessor if you find it valuable. In this walkthrough, we will be using Sass, but you can also use Less, or another alternative.
 421 | 
 422 | First, let’s install the command-line interface for Sass:
 423 | 
 424 | ```
 425 | npm install node-sass --save-dev
 426 | ```
 427 | 
 428 | Then in `package.json`, add the following lines to `scripts`:
 429 | 
 430 | ```diff
 431 |    "scripts": {
 432 | +    "build-css": "node-sass src/ -o src/",
 433 | +    "watch-css": "npm run build-css && node-sass src/ -o src/ --watch --recursive",
 434 |      "start": "react-scripts start",
 435 |      "build": "react-scripts build",
 436 |      "test": "react-scripts test --env=jsdom",
 437 | ```
 438 | 
 439 | >Note: To use a different preprocessor, replace `build-css` and `watch-css` commands according to your preprocessor’s documentation.
 440 | 
 441 | Now you can rename `src/App.css` to `src/App.scss` and run `npm run watch-css`. The watcher will find every Sass file in `src` subdirectories, and create a corresponding CSS file next to it, in our case overwriting `src/App.css`. Since `src/App.js` still imports `src/App.css`, the styles become a part of your application. You can now edit `src/App.scss`, and `src/App.css` will be regenerated.
 442 | 
 443 | To share variables between Sass files, you can use Sass imports. For example, `src/App.scss` and other component style files could include `@import "./shared.scss";` with variable definitions.
 444 | 
 445 | At this point you might want to remove all CSS files from the source control, and add `src/**/*.css` to your `.gitignore` file. It is generally a good practice to keep the build products outside of the source control.
 446 | 
 447 | As a final step, you may find it convenient to run `watch-css` automatically with `npm start`, and run `build-css` as a part of `npm run build`. You can use the `&&` operator to execute two scripts sequentially. However, there is no cross-platform way to run two scripts in parallel, so we will install a package for this:
 448 | 
 449 | ```
 450 | npm install --save-dev npm-run-all
 451 | ```
 452 | 
 453 | Then we can change `start` and `build` scripts to include the CSS preprocessor commands:
 454 | 
 455 | ```diff
 456 |    "scripts": {
 457 |      "build-css": "node-sass src/ -o src/",
 458 |      "watch-css": "npm run build-css && node-sass src/ -o src/ --watch --recursive",
 459 | -    "start": "react-scripts start",
 460 | -    "build": "react-scripts build",
 461 | +    "start-js": "react-scripts start",
 462 | +    "start": "npm-run-all -p watch-css start-js",
 463 | +    "build": "npm run build-css && react-scripts build",
 464 |      "test": "react-scripts test --env=jsdom",
 465 |      "eject": "react-scripts eject"
 466 |    }
 467 | ```
 468 | 
 469 | Now running `npm start` and `npm run build` also builds Sass files. Note that `node-sass` seems to have an [issue recognizing newly created files on some systems](https://github.com/sass/node-sass/issues/1891) so you might need to restart the watcher when you create a file until it’s resolved.
 470 | 
 471 | ## Adding Images and Fonts
 472 | 
 473 | With Webpack, using static assets like images and fonts works similarly to CSS.
 474 | 
 475 | You can **`import` an image right in a JavaScript module**. This tells Webpack to include that image in the bundle. Unlike CSS imports, importing an image or a font gives you a string value. This value is the final image path you can reference in your code.
 476 | 
 477 | Here is an example:
 478 | 
 479 | ```js
 480 | import React from 'react';
 481 | import logo from './logo.png'; // Tell Webpack this JS file uses this image
 482 | 
 483 | console.log(logo); // /logo.84287d09.png
 484 | 
 485 | function Header() {
 486 |   // Import result is the URL of your image
 487 |   return <img src={logo} alt="Logo" />;
 488 | }
 489 | 
 490 | export default Header;
 491 | ```
 492 | 
 493 | This ensures that when the project is built, Webpack will correctly move the images into the build folder, and provide us with correct paths.
 494 | 
 495 | This works in CSS too:
 496 | 
 497 | ```css
 498 | .Logo {
 499 |   background-image: url(./logo.png);
 500 | }
 501 | ```
 502 | 
 503 | Webpack finds all relative module references in CSS (they start with `./`) and replaces them with the final paths from the compiled bundle. If you make a typo or accidentally delete an important file, you will see a compilation error, just like when you import a non-existent JavaScript module. The final filenames in the compiled bundle are generated by Webpack from content hashes. If the file content changes in the future, Webpack will give it a different name in production so you don’t need to worry about long-term caching of assets.
 504 | 
 505 | Please be advised that this is also a custom feature of Webpack.
 506 | 
 507 | **It is not required for React** but many people enjoy it (and React Native uses a similar mechanism for images).<br>
 508 | An alternative way of handling static assets is described in the next section.
 509 | 
 510 | ## Using the `public` Folder
 511 | 
 512 | >Note: this feature is available with `react-scripts@0.5.0` and higher.
 513 | 
 514 | ### Changing the HTML
 515 | 
 516 | The `public` folder contains the HTML file so you can tweak it, for example, to [set the page title](#changing-the-page-title).
 517 | The `<script>` tag with the compiled code will be added to it automatically during the build process.
 518 | 
 519 | ### Adding Assets Outside of the Module System
 520 | 
 521 | You can also add other assets to the `public` folder.
 522 | 
 523 | Note that we normally encourage you to `import` assets in JavaScript files instead.
 524 | For example, see the sections on [adding a stylesheet](#adding-a-stylesheet) and [adding images and fonts](#adding-images-and-fonts).
 525 | This mechanism provides a number of benefits:
 526 | 
 527 | * Scripts and stylesheets get minified and bundled together to avoid extra network requests.
 528 | * Missing files cause compilation errors instead of 404 errors for your users.
 529 | * Result filenames include content hashes so you don’t need to worry about browsers caching their old versions.
 530 | 
 531 | However there is an **escape hatch** that you can use to add an asset outside of the module system.
 532 | 
 533 | If you put a file into the `public` folder, it will **not** be processed by Webpack. Instead it will be copied into the build folder untouched.   To reference assets in the `public` folder, you need to use a special variable called `PUBLIC_URL`.
 534 | 
 535 | Inside `index.html`, you can use it like this:
 536 | 
 537 | ```html
 538 | <link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">
 539 | ```
 540 | 
 541 | Only files inside the `public` folder will be accessible by `%PUBLIC_URL%` prefix. If you need to use a file from `src` or `node_modules`, you’ll have to copy it there to explicitly specify your intention to make this file a part of the build.
 542 | 
 543 | When you run `npm run build`, Create React App will substitute `%PUBLIC_URL%` with a correct absolute path so your project works even if you use client-side routing or host it at a non-root URL.
 544 | 
 545 | In JavaScript code, you can use `process.env.PUBLIC_URL` for similar purposes:
 546 | 
 547 | ```js
 548 | render() {
 549 |   // Note: this is an escape hatch and should be used sparingly!
 550 |   // Normally we recommend using `import` for getting asset URLs
 551 |   // as described in “Adding Images and Fonts” above this section.
 552 |   return <img src={process.env.PUBLIC_URL + '/img/logo.png'} />;
 553 | }
 554 | ```
 555 | 
 556 | Keep in mind the downsides of this approach:
 557 | 
 558 | * None of the files in `public` folder get post-processed or minified.
 559 | * Missing files will not be called at compilation time, and will cause 404 errors for your users.
 560 | * Result filenames won’t include content hashes so you’ll need to add query arguments or rename them every time they change.
 561 | 
 562 | ### When to Use the `public` Folder
 563 | 
 564 | Normally we recommend importing [stylesheets](#adding-a-stylesheet), [images, and fonts](#adding-images-and-fonts) from JavaScript.
 565 | The `public` folder is useful as a workaround for a number of less common cases:
 566 | 
 567 | * You need a file with a specific name in the build output, such as [`manifest.webmanifest`](https://developer.mozilla.org/en-US/docs/Web/Manifest).
 568 | * You have thousands of images and need to dynamically reference their paths.
 569 | * You want to include a small script like [`pace.js`](http://github.hubspot.com/pace/docs/welcome/) outside of the bundled code.
 570 | * Some library may be incompatible with Webpack and you have no other option but to include it as a `<script>` tag.
 571 | 
 572 | Note that if you add a `<script>` that declares global variables, you also need to read the next section on using them.
 573 | 
 574 | ## Using Global Variables
 575 | 
 576 | When you include a script in the HTML file that defines global variables and try to use one of these variables in the code, the linter will complain because it cannot see the definition of the variable.
 577 | 
 578 | You can avoid this by reading the global variable explicitly from the `window` object, for example:
 579 | 
 580 | ```js
 581 | const $ = window.$;
 582 | ```
 583 | 
 584 | This makes it obvious you are using a global variable intentionally rather than because of a typo.
 585 | 
 586 | Alternatively, you can force the linter to ignore any line by adding `// eslint-disable-line` after it.
 587 | 
 588 | ## Adding Bootstrap
 589 | 
 590 | You don’t have to use [React Bootstrap](https://react-bootstrap.github.io) together with React but it is a popular library for integrating Bootstrap with React apps. If you need it, you can integrate it with Create React App by following these steps:
 591 | 
 592 | Install React Bootstrap and Bootstrap from npm. React Bootstrap does not include Bootstrap CSS so this needs to be installed as well:
 593 | 
 594 | ```
 595 | npm install react-bootstrap --save
 596 | npm install bootstrap@3 --save
 597 | ```
 598 | 
 599 | Import Bootstrap CSS and optionally Bootstrap theme CSS in the beginning of your ```src/index.js``` file:
 600 | 
 601 | ```js
 602 | import 'bootstrap/dist/css/bootstrap.css';
 603 | import 'bootstrap/dist/css/bootstrap-theme.css';
 604 | // Put any other imports below so that CSS from your
 605 | // components takes precedence over default styles.
 606 | ```
 607 | 
 608 | Import required React Bootstrap components within ```src/App.js``` file or your custom component files:
 609 | 
 610 | ```js
 611 | import { Navbar, Jumbotron, Button } from 'react-bootstrap';
 612 | ```
 613 | 
 614 | Now you are ready to use the imported React Bootstrap components within your component hierarchy defined in the render method. Here is an example [`App.js`](https://gist.githubusercontent.com/gaearon/85d8c067f6af1e56277c82d19fd4da7b/raw/6158dd991b67284e9fc8d70b9d973efe87659d72/App.js) redone using React Bootstrap.
 615 | 
 616 | ### Using a Custom Theme
 617 | 
 618 | Sometimes you might need to tweak the visual styles of Bootstrap (or equivalent package).<br>
 619 | We suggest the following approach:
 620 | 
 621 | * Create a new package that depends on the package you wish to customize, e.g. Bootstrap.
 622 | * Add the necessary build steps to tweak the theme, and publish your package on npm.
 623 | * Install your own theme npm package as a dependency of your app.
 624 | 
 625 | Here is an example of adding a [customized Bootstrap](https://medium.com/@tacomanator/customizing-create-react-app-aa9ffb88165) that follows these steps.
 626 | 
 627 | ## Adding Flow
 628 | 
 629 | Flow is a static type checker that helps you write code with fewer bugs. Check out this [introduction to using static types in JavaScript](https://medium.com/@preethikasireddy/why-use-static-types-in-javascript-part-1-8382da1e0adb) if you are new to this concept.
 630 | 
 631 | Recent versions of [Flow](http://flowtype.org/) work with Create React App projects out of the box.
 632 | 
 633 | To add Flow to a Create React App project, follow these steps:
 634 | 
 635 | 1. Run `npm install --save-dev flow-bin` (or `yarn add --dev flow-bin`).
 636 | 2. Add `"flow": "flow"` to the `scripts` section of your `package.json`.
 637 | 3. Run `npm run flow -- init` (or `yarn flow -- init`) to create a [`.flowconfig` file](https://flowtype.org/docs/advanced-configuration.html) in the root directory.
 638 | 4. Add `// @flow` to any files you want to type check (for example, to `src/App.js`).
 639 | 
 640 | Now you can run `npm run flow` (or `yarn flow`) to check the files for type errors.
 641 | You can optionally use an IDE like [Nuclide](https://nuclide.io/docs/languages/flow/) for a better integrated experience.
 642 | In the future we plan to integrate it into Create React App even more closely.
 643 | 
 644 | To learn more about Flow, check out [its documentation](https://flowtype.org/).
 645 | 
 646 | ## Adding Custom Environment Variables
 647 | 
 648 | >Note: this feature is available with `react-scripts@0.2.3` and higher.
 649 | 
 650 | Your project can consume variables declared in your environment as if they were declared locally in your JS files. By
 651 | default you will have `NODE_ENV` defined for you, and any other environment variables starting with
 652 | `REACT_APP_`.
 653 | 
 654 | **The environment variables are embedded during the build time**. Since Create React App produces a static HTML/CSS/JS bundle, it can’t possibly read them at runtime. To read them at runtime, you would need to load HTML into memory on the server and replace placeholders in runtime, just like [described here](#injecting-data-from-the-server-into-the-page). Alternatively you can rebuild the app on the server anytime you change them.
 655 | 
 656 | >Note: You must create custom environment variables beginning with `REACT_APP_`. Any other variables except `NODE_ENV` will be ignored to avoid accidentally [exposing a private key on the machine that could have the same name](https://github.com/facebookincubator/create-react-app/issues/865#issuecomment-252199527). Changing any environment variables will require you to restart the development server if it is running.
 657 | 
 658 | These environment variables will be defined for you on `process.env`. For example, having an environment
 659 | variable named `REACT_APP_SECRET_CODE` will be exposed in your JS as `process.env.REACT_APP_SECRET_CODE`.
 660 | 
 661 | There is also a special built-in environment variable called `NODE_ENV`. You can read it from `process.env.NODE_ENV`. When you run `npm start`, it is always equal to `'development'`, when you run `npm test` it is always equal to `'test'`, and when you run `npm run build` to make a production bundle, it is always equal to `'production'`. **You cannot override `NODE_ENV` manually.** This prevents developers from accidentally deploying a slow development build to production.
 662 | 
 663 | These environment variables can be useful for displaying information conditionally based on where the project is
 664 | deployed or consuming sensitive data that lives outside of version control.
 665 | 
 666 | First, you need to have environment variables defined. For example, let’s say you wanted to consume a secret defined
 667 | in the environment inside a `<form>`:
 668 | 
 669 | ```jsx
 670 | render() {
 671 |   return (
 672 |     <div>
 673 |       <small>You are running this application in <b>{process.env.NODE_ENV}</b> mode.</small>
 674 |       <form>
 675 |         <input type="hidden" defaultValue={process.env.REACT_APP_SECRET_CODE} />
 676 |       </form>
 677 |     </div>
 678 |   );
 679 | }
 680 | ```
 681 | 
 682 | During the build, `process.env.REACT_APP_SECRET_CODE` will be replaced with the current value of the `REACT_APP_SECRET_CODE` environment variable. Remember that the `NODE_ENV` variable will be set for you automatically.
 683 | 
 684 | When you load the app in the browser and inspect the `<input>`, you will see its value set to `abcdef`, and the bold text will show the environment provided when using `npm start`:
 685 | 
 686 | ```html
 687 | <div>
 688 |   <small>You are running this application in <b>development</b> mode.</small>
 689 |   <form>
 690 |     <input type="hidden" value="abcdef" />
 691 |   </form>
 692 | </div>
 693 | ```
 694 | 
 695 | The above form is looking for a variable called `REACT_APP_SECRET_CODE` from the environment. In order to consume this
 696 | value, we need to have it defined in the environment. This can be done using two ways: either in your shell or in
 697 | a `.env` file. Both of these ways are described in the next few sections.
 698 | 
 699 | Having access to the `NODE_ENV` is also useful for performing actions conditionally:
 700 | 
 701 | ```js
 702 | if (process.env.NODE_ENV !== 'production') {
 703 |   analytics.disable();
 704 | }
 705 | ```
 706 | 
 707 | When you compile the app with `npm run build`, the minification step will strip out this condition, and the resulting bundle will be smaller.
 708 | 
 709 | ### Referencing Environment Variables in the HTML
 710 | 
 711 | >Note: this feature is available with `react-scripts@0.9.0` and higher.
 712 | 
 713 | You can also access the environment variables starting with `REACT_APP_` in the `public/index.html`. For example:
 714 | 
 715 | ```html
 716 | <title>%REACT_APP_WEBSITE_NAME%</title>
 717 | ```
 718 | 
 719 | Note that the caveats from the above section apply:
 720 | 
 721 | * Apart from a few built-in variables (`NODE_ENV` and `PUBLIC_URL`), variable names must start with `REACT_APP_` to work.
 722 | * The environment variables are injected at build time. If you need to inject them at runtime, [follow this approach instead](#generating-dynamic-meta-tags-on-the-server).
 723 | 
 724 | ### Adding Temporary Environment Variables In Your Shell
 725 | 
 726 | Defining environment variables can vary between OSes. It’s also important to know that this manner is temporary for the
 727 | life of the shell session.
 728 | 
 729 | #### Windows (cmd.exe)
 730 | 
 731 | ```cmd
 732 | set REACT_APP_SECRET_CODE=abcdef&&npm start
 733 | ```
 734 | 
 735 | (Note: the lack of whitespace is intentional.)
 736 | 
 737 | #### Linux, macOS (Bash)
 738 | 
 739 | ```bash
 740 | REACT_APP_SECRET_CODE=abcdef npm start
 741 | ```
 742 | 
 743 | ### Adding Development Environment Variables In `.env`
 744 | 
 745 | >Note: this feature is available with `react-scripts@0.5.0` and higher.
 746 | 
 747 | To define permanent environment variables, create a file called `.env` in the root of your project:
 748 | 
 749 | ```
 750 | REACT_APP_SECRET_CODE=abcdef
 751 | ```
 752 | 
 753 | These variables will act as the defaults if the machine does not explicitly set them.<br>
 754 | Please refer to the [dotenv documentation](https://github.com/motdotla/dotenv) for more details.
 755 | 
 756 | >Note: If you are defining environment variables for development, your CI and/or hosting platform will most likely need
 757 | these defined as well. Consult their documentation how to do this. For example, see the documentation for [Travis CI](https://docs.travis-ci.com/user/environment-variables/) or [Heroku](https://devcenter.heroku.com/articles/config-vars).
 758 | 
 759 | ## Can I Use Decorators?
 760 | 
 761 | Many popular libraries use [decorators](https://medium.com/google-developers/exploring-es7-decorators-76ecb65fb841) in their documentation.<br>
 762 | Create React App doesn’t support decorator syntax at the moment because:
 763 | 
 764 | * It is an experimental proposal and is subject to change.
 765 | * The current specification version is not officially supported by Babel.
 766 | * If the specification changes, we won’t be able to write a codemod because we don’t use them internally at Facebook.
 767 | 
 768 | However in many cases you can rewrite decorator-based code without decorators just as fine.<br>
 769 | Please refer to these two threads for reference:
 770 | 
 771 | * [#214](https://github.com/facebookincubator/create-react-app/issues/214)
 772 | * [#411](https://github.com/facebookincubator/create-react-app/issues/411)
 773 | 
 774 | Create React App will add decorator support when the specification advances to a stable stage.
 775 | 
 776 | ## Integrating with an API Backend
 777 | 
 778 | These tutorials will help you to integrate your app with an API backend running on another port,
 779 | using `fetch()` to access it.
 780 | 
 781 | ### Node
 782 | Check out [this tutorial](https://www.fullstackreact.com/articles/using-create-react-app-with-a-server/).
 783 | You can find the companion GitHub repository [here](https://github.com/fullstackreact/food-lookup-demo).
 784 | 
 785 | ### Ruby on Rails
 786 | 
 787 | Check out [this tutorial](https://www.fullstackreact.com/articles/how-to-get-create-react-app-to-work-with-your-rails-api/).
 788 | You can find the companion GitHub repository [here](https://github.com/fullstackreact/food-lookup-demo-rails).
 789 | 
 790 | ## Proxying API Requests in Development
 791 | 
 792 | >Note: this feature is available with `react-scripts@0.2.3` and higher.
 793 | 
 794 | People often serve the front-end React app from the same host and port as their backend implementation.<br>
 795 | For example, a production setup might look like this after the app is deployed:
 796 | 
 797 | ```
 798 | /             - static server returns index.html with React app
 799 | /todos        - static server returns index.html with React app
 800 | /api/todos    - server handles any /api/* requests using the backend implementation
 801 | ```
 802 | 
 803 | Such setup is **not** required. However, if you **do** have a setup like this, it is convenient to write requests like `fetch('/api/todos')` without worrying about redirecting them to another host or port during development.
 804 | 
 805 | To tell the development server to proxy any unknown requests to your API server in development, add a `proxy` field to your `package.json`, for example:
 806 | 
 807 | ```js
 808 |   "proxy": "http://localhost:4000",
 809 | ```
 810 | 
 811 | This way, when you `fetch('/api/todos')` in development, the development server will recognize that it’s not a static asset, and will proxy your request to `http://localhost:4000/api/todos` as a fallback. The development server will only attempt to send requests without a `text/html` accept header to the proxy.
 812 | 
 813 | Conveniently, this avoids [CORS issues](http://stackoverflow.com/questions/21854516/understanding-ajax-cors-and-security-considerations) and error messages like this in development:
 814 | 
 815 | ```
 816 | Fetch API cannot load http://localhost:4000/api/todos. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:3000' is therefore not allowed access. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.
 817 | ```
 818 | 
 819 | Keep in mind that `proxy` only has effect in development (with `npm start`), and it is up to you to ensure that URLs like `/api/todos` point to the right thing in production. You don’t have to use the `/api` prefix. Any unrecognized request without a `text/html` accept header will be redirected to the specified `proxy`.
 820 | 
 821 | The `proxy` option supports HTTP, HTTPS and WebSocket connections.<br>
 822 | If the `proxy` option is **not** flexible enough for you, alternatively you can:
 823 | 
 824 | * Enable CORS on your server ([here’s how to do it for Express](http://enable-cors.org/server_expressjs.html)).
 825 | * Use [environment variables](#adding-custom-environment-variables) to inject the right server host and port into your app.
 826 | 
 827 | ## Using HTTPS in Development
 828 | 
 829 | >Note: this feature is available with `react-scripts@0.4.0` and higher.
 830 | 
 831 | You may require the dev server to serve pages over HTTPS. One particular case where this could be useful is when using [the "proxy" feature](#proxying-api-requests-in-development) to proxy requests to an API server when that API server is itself serving HTTPS.
 832 | 
 833 | To do this, set the `HTTPS` environment variable to `true`, then start the dev server as usual with `npm start`:
 834 | 
 835 | #### Windows (cmd.exe)
 836 | 
 837 | ```cmd
 838 | set HTTPS=true&&npm start
 839 | ```
 840 | 
 841 | (Note: the lack of whitespace is intentional.)
 842 | 
 843 | #### Linux, macOS (Bash)
 844 | 
 845 | ```bash
 846 | HTTPS=true npm start
 847 | ```
 848 | 
 849 | Note that the server will use a self-signed certificate, so your web browser will almost definitely display a warning upon accessing the page.
 850 | 
 851 | ## Generating Dynamic `<meta>` Tags on the Server
 852 | 
 853 | Since Create React App doesn’t support server rendering, you might be wondering how to make `<meta>` tags dynamic and reflect the current URL. To solve this, we recommend to add placeholders into the HTML, like this:
 854 | 
 855 | ```html
 856 | <!doctype html>
 857 | <html lang="en">
 858 |   <head>
 859 |     <meta property="og:title" content="__OG_TITLE__">
 860 |     <meta property="og:description" content="__OG_DESCRIPTION__">
 861 | ```
 862 | 
 863 | Then, on the server, regardless of the backend you use, you can read `index.html` into memory and replace `__OG_TITLE__`, `__OG_DESCRIPTION__`, and any other placeholders with values depending on the current URL. Just make sure to sanitize and escape the interpolated values so that they are safe to embed into HTML!
 864 | 
 865 | If you use a Node server, you can even share the route matching logic between the client and the server. However duplicating it also works fine in simple cases.
 866 | 
 867 | ## Pre-Rendering into Static HTML Files
 868 | 
 869 | If you’re hosting your `build` with a static hosting provider you can use [react-snapshot](https://www.npmjs.com/package/react-snapshot) to generate HTML pages for each route, or relative link, in your application. These pages will then seamlessly become active, or “hydrated”, when the JavaScript bundle has loaded.
 870 | 
 871 | There are also opportunities to use this outside of static hosting, to take the pressure off the server when generating and caching routes.
 872 | 
 873 | The primary benefit of pre-rendering is that you get the core content of each page _with_ the HTML payload—regardless of whether or not your JavaScript bundle successfully downloads. It also increases the likelihood that each route of your application will be picked up by search engines.
 874 | 
 875 | You can read more about [zero-configuration pre-rendering (also called snapshotting) here](https://medium.com/superhighfives/an-almost-static-stack-6df0a2791319).
 876 | 
 877 | ## Injecting Data from the Server into the Page
 878 | 
 879 | Similarly to the previous section, you can leave some placeholders in the HTML that inject global variables, for example:
 880 | 
 881 | ```js
 882 | <!doctype html>
 883 | <html lang="en">
 884 |   <head>
 885 |     <script>
 886 |       window.SERVER_DATA = __SERVER_DATA__;
 887 |     </script>
 888 | ```
 889 | 
 890 | Then, on the server, you can replace `__SERVER_DATA__` with a JSON of real data right before sending the response. The client code can then read `window.SERVER_DATA` to use it. **Make sure to [sanitize the JSON before sending it to the client](https://medium.com/node-security/the-most-common-xss-vulnerability-in-react-js-applications-2bdffbcc1fa0) as it makes your app vulnerable to XSS attacks.**
 891 | 
 892 | ## Running Tests
 893 | 
 894 | >Note: this feature is available with `react-scripts@0.3.0` and higher.<br>
 895 | >[Read the migration guide to learn how to enable it in older projects!](https://github.com/facebookincubator/create-react-app/blob/master/CHANGELOG.md#migrating-from-023-to-030)
 896 | 
 897 | Create React App uses [Jest](https://facebook.github.io/jest/) as its test runner. To prepare for this integration, we did a [major revamp](https://facebook.github.io/jest/blog/2016/09/01/jest-15.html) of Jest so if you heard bad things about it years ago, give it another try.
 898 | 
 899 | Jest is a Node-based runner. This means that the tests always run in a Node environment and not in a real browser. This lets us enable fast iteration speed and prevent flakiness.
 900 | 
 901 | While Jest provides browser globals such as `window` thanks to [jsdom](https://github.com/tmpvar/jsdom), they are only approximations of the real browser behavior. Jest is intended to be used for unit tests of your logic and your components rather than the DOM quirks.
 902 | 
 903 | We recommend that you use a separate tool for browser end-to-end tests if you need them. They are beyond the scope of Create React App.
 904 | 
 905 | ### Filename Conventions
 906 | 
 907 | Jest will look for test files with any of the following popular naming conventions:
 908 | 
 909 | * Files with `.js` suffix in `__tests__` folders.
 910 | * Files with `.test.js` suffix.
 911 | * Files with `.spec.js` suffix.
 912 | 
 913 | The `.test.js` / `.spec.js` files (or the `__tests__` folders) can be located at any depth under the `src` top level folder.
 914 | 
 915 | We recommend to put the test files (or `__tests__` folders) next to the code they are testing so that relative imports appear shorter. For example, if `App.test.js` and `App.js` are in the same folder, the test just needs to `import App from './App'` instead of a long relative path. Colocation also helps find tests more quickly in larger projects.
 916 | 
 917 | ### Command Line Interface
 918 | 
 919 | When you run `npm test`, Jest will launch in the watch mode. Every time you save a file, it will re-run the tests, just like `npm start` recompiles the code.
 920 | 
 921 | The watcher includes an interactive command-line interface with the ability to run all tests, or focus on a search pattern. It is designed this way so that you can keep it open and enjoy fast re-runs. You can learn the commands from the “Watch Usage” note that the watcher prints after every run:
 922 | 
 923 | ![Jest watch mode](http://facebook.github.io/jest/img/blog/15-watch.gif)
 924 | 
 925 | ### Version Control Integration
 926 | 
 927 | By default, when you run `npm test`, Jest will only run the tests related to files changed since the last commit. This is an optimization designed to make your tests runs fast regardless of how many tests you have. However it assumes that you don’t often commit the code that doesn’t pass the tests.
 928 | 
 929 | Jest will always explicitly mention that it only ran tests related to the files changed since the last commit. You can also press `a` in the watch mode to force Jest to run all tests.
 930 | 
 931 | Jest will always run all tests on a [continuous integration](#continuous-integration) server or if the project is not inside a Git or Mercurial repository.
 932 | 
 933 | ### Writing Tests
 934 | 
 935 | To create tests, add `it()` (or `test()`) blocks with the name of the test and its code. You may optionally wrap them in `describe()` blocks for logical grouping but this is neither required nor recommended.
 936 | 
 937 | Jest provides a built-in `expect()` global function for making assertions. A basic test could look like this:
 938 | 
 939 | ```js
 940 | import sum from './sum';
 941 | 
 942 | it('sums numbers', () => {
 943 |   expect(sum(1, 2)).toEqual(3);
 944 |   expect(sum(2, 2)).toEqual(4);
 945 | });
 946 | ```
 947 | 
 948 | All `expect()` matchers supported by Jest are [extensively documented here](http://facebook.github.io/jest/docs/expect.html).<br>
 949 | You can also use [`jest.fn()` and `expect(fn).toBeCalled()`](http://facebook.github.io/jest/docs/expect.html#tohavebeencalled) to create “spies” or mock functions.
 950 | 
 951 | ### Testing Components
 952 | 
 953 | There is a broad spectrum of component testing techniques. They range from a “smoke test” verifying that a component renders without throwing, to shallow rendering and testing some of the output, to full rendering and testing component lifecycle and state changes.
 954 | 
 955 | Different projects choose different testing tradeoffs based on how often components change, and how much logic they contain. If you haven’t decided on a testing strategy yet, we recommend that you start with creating simple smoke tests for your components:
 956 | 
 957 | ```js
 958 | import React from 'react';
 959 | import ReactDOM from 'react-dom';
 960 | import App from './App';
 961 | 
 962 | it('renders without crashing', () => {
 963 |   const div = document.createElement('div');
 964 |   ReactDOM.render(<App />, div);
 965 | });
 966 | ```
 967 | 
 968 | This test mounts a component and makes sure that it didn’t throw during rendering. Tests like this provide a lot value with very little effort so they are great as a starting point, and this is the test you will find in `src/App.test.js`.
 969 | 
 970 | When you encounter bugs caused by changing components, you will gain a deeper insight into which parts of them are worth testing in your application. This might be a good time to introduce more specific tests asserting specific expected output or behavior.
 971 | 
 972 | If you’d like to test components in isolation from the child components they render, we recommend using [`shallow()` rendering API](http://airbnb.io/enzyme/docs/api/shallow.html) from [Enzyme](http://airbnb.io/enzyme/). You can write a smoke test with it too:
 973 | 
 974 | ```sh
 975 | npm install --save-dev enzyme react-addons-test-utils
 976 | ```
 977 | 
 978 | ```js
 979 | import React from 'react';
 980 | import { shallow } from 'enzyme';
 981 | import App from './App';
 982 | 
 983 | it('renders without crashing', () => {
 984 |   shallow(<App />);
 985 | });
 986 | ```
 987 | 
 988 | Unlike the previous smoke test using `ReactDOM.render()`, this test only renders `<App>` and doesn’t go deeper. For example, even if `<App>` itself renders a `<Button>` that throws, this test will pass. Shallow rendering is great for isolated unit tests, but you may still want to create some full rendering tests to ensure the components integrate correctly. Enzyme supports [full rendering with `mount()`](http://airbnb.io/enzyme/docs/api/mount.html), and you can also use it for testing state changes and component lifecycle.
 989 | 
 990 | You can read the [Enzyme documentation](http://airbnb.io/enzyme/) for more testing techniques. Enzyme documentation uses Chai and Sinon for assertions but you don’t have to use them because Jest provides built-in `expect()` and `jest.fn()` for spies.
 991 | 
 992 | Here is an example from Enzyme documentation that asserts specific output, rewritten to use Jest matchers:
 993 | 
 994 | ```js
 995 | import React from 'react';
 996 | import { shallow } from 'enzyme';
 997 | import App from './App';
 998 | 
 999 | it('renders welcome message', () => {
1000 |   const wrapper = shallow(<App />);
1001 |   const welcome = <h2>Welcome to React</h2>;
1002 |   // expect(wrapper.contains(welcome)).to.equal(true);
1003 |   expect(wrapper.contains(welcome)).toEqual(true);
1004 | });
1005 | ```
1006 | 
1007 | All Jest matchers are [extensively documented here](http://facebook.github.io/jest/docs/expect.html).<br>
1008 | Nevertheless you can use a third-party assertion library like [Chai](http://chaijs.com/) if you want to, as described below.
1009 | 
1010 | Additionally, you might find [jest-enzyme](https://github.com/blainekasten/enzyme-matchers) helpful to simplify your tests with readable matchers. The above `contains` code can be written simpler with jest-enzyme.
1011 | 
1012 | ```js
1013 | expect(wrapper).toContainReact(welcome)
1014 | ```
1015 | 
1016 | To setup jest-enzyme with Create React App, follow the instructions for [initializing your test environment](#initializing-test-environment) to import `jest-enzyme`.
1017 | 
1018 | ```sh
1019 | npm install --save-dev jest-enzyme
1020 | ```
1021 | 
1022 | ```js
1023 | // src/setupTests.js
1024 | import 'jest-enzyme';
1025 | ```
1026 | 
1027 | 
1028 | ### Using Third Party Assertion Libraries
1029 | 
1030 | We recommend that you use `expect()` for assertions and `jest.fn()` for spies. If you are having issues with them please [file those against Jest](https://github.com/facebook/jest/issues/new), and we’ll fix them. We intend to keep making them better for React, supporting, for example, [pretty-printing React elements as JSX](https://github.com/facebook/jest/pull/1566).
1031 | 
1032 | However, if you are used to other libraries, such as [Chai](http://chaijs.com/) and [Sinon](http://sinonjs.org/), or if you have existing code using them that you’d like to port over, you can import them normally like this:
1033 | 
1034 | ```js
1035 | import sinon from 'sinon';
1036 | import { expect } from 'chai';
1037 | ```
1038 | 
1039 | and then use them in your tests like you normally do.
1040 | 
1041 | ### Initializing Test Environment
1042 | 
1043 | >Note: this feature is available with `react-scripts@0.4.0` and higher.
1044 | 
1045 | If your app uses a browser API that you need to mock in your tests or if you just need a global setup before running your tests, add a `src/setupTests.js` to your project. It will be automatically executed before running your tests.
1046 | 
1047 | For example:
1048 | 
1049 | #### `src/setupTests.js`
1050 | ```js
1051 | const localStorageMock = {
1052 |   getItem: jest.fn(),
1053 |   setItem: jest.fn(),
1054 |   clear: jest.fn()
1055 | };
1056 | global.localStorage = localStorageMock
1057 | ```
1058 | 
1059 | ### Focusing and Excluding Tests
1060 | 
1061 | You can replace `it()` with `xit()` to temporarily exclude a test from being executed.<br>
1062 | Similarly, `fit()` lets you focus on a specific test without running any other tests.
1063 | 
1064 | ### Coverage Reporting
1065 | 
1066 | Jest has an integrated coverage reporter that works well with ES6 and requires no configuration.<br>
1067 | Run `npm test -- --coverage` (note extra `--` in the middle) to include a coverage report like this:
1068 | 
1069 | ![coverage report](http://i.imgur.com/5bFhnTS.png)
1070 | 
1071 | Note that tests run much slower with coverage so it is recommended to run it separately from your normal workflow.
1072 | 
1073 | ### Continuous Integration
1074 | 
1075 | By default `npm test` runs the watcher with interactive CLI. However, you can force it to run tests once and finish the process by setting an environment variable called `CI`.
1076 | 
1077 | When creating a build of your application with `npm run build` linter warnings are not checked by default. Like `npm test`, you can force the build to perform a linter warning check by setting the environment variable `CI`. If any warnings are encountered then the build fails.
1078 | 
1079 | Popular CI servers already set the environment variable `CI` by default but you can do this yourself too:
1080 | 
1081 | ### On CI servers
1082 | #### Travis CI
1083 | 
1084 | 1. Following the [Travis Getting started](https://docs.travis-ci.com/user/getting-started/) guide for syncing your GitHub repository with Travis.  You may need to initialize some settings manually in your [profile](https://travis-ci.org/profile) page.
1085 | 1. Add a `.travis.yml` file to your git repository.
1086 | ```
1087 | language: node_js
1088 | node_js:
1089 |   - 4
1090 |   - 6
1091 | cache:
1092 |   directories:
1093 |     - node_modules
1094 | script:
1095 |   - npm test
1096 |   - npm run build
1097 | ```
1098 | 1. Trigger your first build with a git push.
1099 | 1. [Customize your Travis CI Build](https://docs.travis-ci.com/user/customizing-the-build/) if needed.
1100 | 
1101 | ### On your own environment
1102 | ##### Windows (cmd.exe)
1103 | 
1104 | ```cmd
1105 | set CI=true&&npm test
1106 | ```
1107 | 
1108 | ```cmd
1109 | set CI=true&&npm run build
1110 | ```
1111 | 
1112 | (Note: the lack of whitespace is intentional.)
1113 | 
1114 | ##### Linux, macOS (Bash)
1115 | 
1116 | ```bash
1117 | CI=true npm test
1118 | ```
1119 | 
1120 | ```bash
1121 | CI=true npm run build
1122 | ```
1123 | 
1124 | The test command will force Jest to run tests once instead of launching the watcher.
1125 | 
1126 | >  If you find yourself doing this often in development, please [file an issue](https://github.com/facebookincubator/create-react-app/issues/new) to tell us about your use case because we want to make watcher the best experience and are open to changing how it works to accommodate more workflows.
1127 | 
1128 | The build command will check for linter warnings and fail if any are found.
1129 | 
1130 | ### Disabling jsdom
1131 | 
1132 | By default, the `package.json` of the generated project looks like this:
1133 | 
1134 | ```js
1135 |   // ...
1136 |   "scripts": {
1137 |     // ...
1138 |     "test": "react-scripts test --env=jsdom"
1139 |   }
1140 | ```
1141 | 
1142 | If you know that none of your tests depend on [jsdom](https://github.com/tmpvar/jsdom), you can safely remove `--env=jsdom`, and your tests will run faster.<br>
1143 | To help you make up your mind, here is a list of APIs that **need jsdom**:
1144 | 
1145 | * Any browser globals like `window` and `document`
1146 | * [`ReactDOM.render()`](https://facebook.github.io/react/docs/top-level-api.html#reactdom.render)
1147 | * [`TestUtils.renderIntoDocument()`](https://facebook.github.io/react/docs/test-utils.html#renderintodocument) ([a shortcut](https://github.com/facebook/react/blob/34761cf9a252964abfaab6faf74d473ad95d1f21/src/test/ReactTestUtils.js#L83-L91) for the above)
1148 | * [`mount()`](http://airbnb.io/enzyme/docs/api/mount.html) in [Enzyme](http://airbnb.io/enzyme/index.html)
1149 | 
1150 | In contrast, **jsdom is not needed** for the following APIs:
1151 | 
1152 | * [`TestUtils.createRenderer()`](https://facebook.github.io/react/docs/test-utils.html#shallow-rendering) (shallow rendering)
1153 | * [`shallow()`](http://airbnb.io/enzyme/docs/api/shallow.html) in [Enzyme](http://airbnb.io/enzyme/index.html)
1154 | 
1155 | Finally, jsdom is also not needed for [snapshot testing](http://facebook.github.io/jest/blog/2016/07/27/jest-14.html).
1156 | 
1157 | ### Snapshot Testing
1158 | 
1159 | Snapshot testing is a feature of Jest that automatically generates text snapshots of your components and saves them on the disk so if the UI output changes, you get notified without manually writing any assertions on the component output. [Read more about snapshot testing.](http://facebook.github.io/jest/blog/2016/07/27/jest-14.html)
1160 | 
1161 | ### Editor Integration
1162 | 
1163 | If you use [Visual Studio Code](https://code.visualstudio.com), there is a [Jest extension](https://github.com/orta/vscode-jest) which works with Create React App out of the box. This provides a lot of IDE-like features while using a text editor: showing the status of a test run with potential fail messages inline, starting and stopping the watcher automatically, and offering one-click snapshot updates.
1164 | 
1165 | ![VS Code Jest Preview](https://cloud.githubusercontent.com/assets/49038/20795349/a032308a-b7c8-11e6-9b34-7eeac781003f.png)
1166 | 
1167 | ## Developing Components in Isolation
1168 | 
1169 | Usually, in an app, you have a lot of UI components, and each of them has many different states.
1170 | For an example, a simple button component could have following states:
1171 | 
1172 | * With a text label.
1173 | * With an emoji.
1174 | * In the disabled mode.
1175 | 
1176 | Usually, it’s hard to see these states without running a sample app or some examples.
1177 | 
1178 | Create React App doesn’t include any tools for this by default, but you can easily add [React Storybook](https://github.com/kadirahq/react-storybook) to your project. **It is a third-party tool that lets you develop components and see all their states in isolation from your app**.
1179 | 
1180 | ![React Storybook Demo](http://i.imgur.com/7CIAWpB.gif)
1181 | 
1182 | You can also deploy your Storybook as a static app. This way, everyone in your team can view and review different states of UI components without starting a backend server or creating an account in your app.
1183 | 
1184 | **Here’s how to setup your app with Storybook:**
1185 | 
1186 | First, install the following npm package globally:
1187 | 
1188 | ```sh
1189 | npm install -g getstorybook
1190 | ```
1191 | 
1192 | Then, run the following command inside your app’s directory:
1193 | 
1194 | ```sh
1195 | getstorybook
1196 | ```
1197 | 
1198 | After that, follow the instructions on the screen.
1199 | 
1200 | Learn more about React Storybook:
1201 | 
1202 | * Screencast: [Getting Started with React Storybook](https://egghead.io/lessons/react-getting-started-with-react-storybook)
1203 | * [GitHub Repo](https://github.com/kadirahq/react-storybook)
1204 | * [Documentation](https://getstorybook.io/docs)
1205 | * [Snapshot Testing](https://github.com/kadirahq/storyshots) with React Storybook
1206 | 
1207 | ## Making a Progressive Web App
1208 | 
1209 | You can turn your React app into a [Progressive Web App](https://developers.google.com/web/progressive-web-apps/) by following the steps in [this repository](https://github.com/jeffposnick/create-react-pwa).
1210 | 
1211 | ## Deployment
1212 | 
1213 | `npm run build` creates a `build` directory with a production build of your app. Set up your favourite HTTP server so that a visitor to your site is served `index.html`, and requests to static paths like `/static/js/main.<hash>.js` are served with the contents of the `/static/js/main.<hash>.js` file.
1214 | 
1215 | ### Static Server
1216 | 
1217 | For environments using [Node](https://nodejs.org/), the easiest way to handle this would be to install [serve](https://github.com/zeit/serve) and let it handle the rest:
1218 | 
1219 | ```sh
1220 | npm install -g serve
1221 | serve -s build
1222 | ```
1223 | 
1224 | The last command shown above will serve your static site on the port **5000**. Like many of [serve](https://github.com/zeit/serve)’s internal settings, the port can be adjusted using the `-p` or `--port` flags.
1225 | 
1226 | Run this command to get a full list of the options available:
1227 | 
1228 | ```sh
1229 | serve -h
1230 | ```
1231 | 
1232 | ### Other Solutions
1233 | 
1234 | You don’t necessarily need a static server in order to run a Create React App project in production. It works just as fine integrated into an existing dynamic one.
1235 | 
1236 | Here’s a programmatic example using [Node](https://nodejs.org/) and [Express](http://expressjs.com/):
1237 | 
1238 | ```javascript
1239 | const express = require('express');
1240 | const path = require('path');
1241 | const app = express();
1242 | 
1243 | app.use(express.static('./build'));
1244 | 
1245 | app.get('/', function (req, res) {
1246 |   res.sendFile(path.join(__dirname, './build', 'index.html'));
1247 | });
1248 | 
1249 | app.listen(9000);
1250 | ```
1251 | 
1252 | The choice of your server software isn’t important either. Since Create React App is completely platform-agnostic, there’s no need to explicitly use Node.
1253 | 
1254 | The `build` folder with static assets is the only output produced by Create React App.
1255 | 
1256 | However this is not quite enough if you use client-side routing. Read the next section if you want to support URLs like `/todos/42` in your single-page app.
1257 | 
1258 | ### Serving Apps with Client-Side Routing
1259 | 
1260 | If you use routers that use the HTML5 [`pushState` history API](https://developer.mozilla.org/en-US/docs/Web/API/History_API#Adding_and_modifying_history_entries) under the hood (for example, [React Router](https://github.com/ReactTraining/react-router) with `browserHistory`), many static file servers will fail. For example, if you used React Router with a route for `/todos/42`, the development server will respond to `localhost:3000/todos/42` properly, but an Express serving a production build as above will not.
1261 | 
1262 | This is because when there is a fresh page load for a `/todos/42`, the server looks for the file `build/todos/42` and does not find it. The server needs to be configured to respond to a request to `/todos/42` by serving `index.html`. For example, we can amend our Express example above to serve `index.html` for any unknown paths:
1263 | 
1264 | ```diff
1265 |  app.use(express.static('./build'));
1266 | 
1267 | -app.get('/', function (req, res) {
1268 | +app.get('/*', function (req, res) {
1269 |    res.sendFile(path.join(__dirname, './build', 'index.html'));
1270 |  });
1271 | ```
1272 | 
1273 | If you’re using [Apache](https://httpd.apache.org/), you need to create a `.htaccess` file in the `public` folder that looks like this:
1274 | 
1275 | ```
1276 |     Options -MultiViews
1277 |     RewriteEngine On
1278 |     RewriteCond %{REQUEST_FILENAME} !-f
1279 |     RewriteRule ^ index.html [QSA,L]
1280 | ```
1281 | 
1282 | It will get copied to the `build` folder when you run `npm run build`.
1283 | 
1284 | Now requests to `/todos/42` will be handled correctly both in development and in production.
1285 | 
1286 | ### Building for Relative Paths
1287 | 
1288 | By default, Create React App produces a build assuming your app is hosted at the server root.<br>
1289 | To override this, specify the `homepage` in your `package.json`, for example:
1290 | 
1291 | ```js
1292 |   "homepage": "http://mywebsite.com/relativepath",
1293 | ```
1294 | 
1295 | This will let Create React App correctly infer the root path to use in the generated HTML file.
1296 | 
1297 | #### Serving the Same Build from Different Paths
1298 | 
1299 | >Note: this feature is available with `react-scripts@0.9.0` and higher.
1300 | 
1301 | If you are not using the HTML5 `pushState` history API or not using client-side routing at all, it is unnecessary to specify the URL from which your app will be served. Instead, you can put this in your `package.json`:
1302 | 
1303 | ```js
1304 |   "homepage": ".",
1305 | ```
1306 | 
1307 | This will make sure that all the asset paths are relative to `index.html`. You will then be able to move your app from `http://mywebsite.com` to `http://mywebsite.com/relativepath` or even `http://mywebsite.com/relative/path` without having to rebuild it.
1308 | 
1309 | ### Azure
1310 | 
1311 | See [this](https://medium.com/@to_pe/deploying-create-react-app-on-microsoft-azure-c0f6686a4321) blog post on how to deploy your React app to [Microsoft Azure](https://azure.microsoft.com/).
1312 | 
1313 | ### Firebase
1314 | 
1315 | Install the Firebase CLI if you haven’t already by running `npm install -g firebase-tools`. Sign up for a [Firebase account](https://console.firebase.google.com/) and create a new project. Run `firebase login` and login with your previous created Firebase account.
1316 | 
1317 | Then run the `firebase init` command from your project’s root. You need to choose the **Hosting: Configure and deploy Firebase Hosting sites** and choose the Firebase project you created in the previous step. You will need to agree with `database.rules.json` being created, choose `build` as the public directory, and also agree to **Configure as a single-page app** by replying with `y`.
1318 | 
1319 | ```sh
1320 |     === Project Setup
1321 | 
1322 |     First, let's associate this project directory with a Firebase project.
1323 |     You can create multiple project aliases by running firebase use --add,
1324 |     but for now we'll just set up a default project.
1325 | 
1326 |     ? What Firebase project do you want to associate as default? Example app (example-app-fd690)
1327 | 
1328 |     === Database Setup
1329 | 
1330 |     Firebase Realtime Database Rules allow you to define how your data should be
1331 |     structured and when your data can be read from and written to.
1332 | 
1333 |     ? What file should be used for Database Rules? database.rules.json
1334 |     ✔  Database Rules for example-app-fd690 have been downloaded to database.rules.json.
1335 |     Future modifications to database.rules.json will update Database Rules when you run
1336 |     firebase deploy.
1337 | 
1338 |     === Hosting Setup
1339 | 
1340 |     Your public directory is the folder (relative to your project directory) that
1341 |     will contain Hosting assets to uploaded with firebase deploy. If you
1342 |     have a build process for your assets, use your build's output directory.
1343 | 
1344 |     ? What do you want to use as your public directory? build
1345 |     ? Configure as a single-page app (rewrite all urls to /index.html)? Yes
1346 |     ✔  Wrote build/index.html
1347 | 
1348 |     i  Writing configuration info to firebase.json...
1349 |     i  Writing project information to .firebaserc...
1350 | 
1351 |     ✔  Firebase initialization complete!
1352 | ```
1353 | 
1354 | Now, after you create a production build with `npm run build`, you can deploy it by running `firebase deploy`.
1355 | 
1356 | ```sh
1357 |     === Deploying to 'example-app-fd690'...
1358 | 
1359 |     i  deploying database, hosting
1360 |     ✔  database: rules ready to deploy.
1361 |     i  hosting: preparing build directory for upload...
1362 |     Uploading: [==============================          ] 75%✔  hosting: build folder uploaded successfully
1363 |     ✔  hosting: 8 files uploaded successfully
1364 |     i  starting release process (may take several minutes)...
1365 | 
1366 |     ✔  Deploy complete!
1367 | 
1368 |     Project Console: https://console.firebase.google.com/project/example-app-fd690/overview
1369 |     Hosting URL: https://example-app-fd690.firebaseapp.com
1370 | ```
1371 | 
1372 | For more information see [Add Firebase to your JavaScript Project](https://firebase.google.com/docs/web/setup).
1373 | 
1374 | ### GitHub Pages
1375 | 
1376 | >Note: this feature is available with `react-scripts@0.2.0` and higher.
1377 | 
1378 | #### Step 1: Add `homepage` to `package.json`
1379 | 
1380 | **The step below is important!**<br>
1381 | **If you skip it, your app will not deploy correctly.**
1382 | 
1383 | Open your `package.json` and add a `homepage` field:
1384 | 
1385 | ```js
1386 |   "homepage": "https://myusername.github.io/my-app",
1387 | ```
1388 | 
1389 | Create React App uses the `homepage` field to determine the root URL in the built HTML file.
1390 | 
1391 | #### Step 2: Install `gh-pages` and add `deploy` to `scripts` in `package.json`
1392 | 
1393 | Now, whenever you run `npm run build`, you will see a cheat sheet with instructions on how to deploy to GitHub Pages.
1394 | 
1395 | To publish it at [https://myusername.github.io/my-app](https://myusername.github.io/my-app), run:
1396 | 
1397 | ```sh
1398 | npm install --save-dev gh-pages
1399 | ```
1400 | 
1401 | Add the following scripts in your `package.json`:
1402 | 
1403 | ```js
1404 |   // ...
1405 |   "scripts": {
1406 |     // ...
1407 |     "predeploy": "npm run build",
1408 |     "deploy": "gh-pages -d build"
1409 |   }
1410 | ```
1411 | 
1412 | The `predeploy` script will run automatically before `deploy` is run.
1413 | 
1414 | #### Step 3: Deploy the site by running `npm run deploy`
1415 | 
1416 | Then run:
1417 | 
1418 | ```sh
1419 | npm run deploy
1420 | ```
1421 | 
1422 | #### Step 4: Ensure your project’s settings use `gh-pages`
1423 | 
1424 | Finally, make sure **GitHub Pages** option in your GitHub project settings is set to use the `gh-pages` branch:
1425 | 
1426 | <img src="http://i.imgur.com/HUjEr9l.png" width="500" alt="gh-pages branch setting">
1427 | 
1428 | #### Step 5: Optionally, configure the domain
1429 | 
1430 | You can configure a custom domain with GitHub Pages by adding a `CNAME` file to the `public/` folder.
1431 | 
1432 | #### Notes on client-side routing
1433 | 
1434 | GitHub Pages doesn’t support routers that use the HTML5 `pushState` history API under the hood (for example, React Router using `browserHistory`). This is because when there is a fresh page load for a url like `http://user.github.io/todomvc/todos/42`, where `/todos/42` is a frontend route, the GitHub Pages server returns 404 because it knows nothing of `/todos/42`. If you want to add a router to a project hosted on GitHub Pages, here are a couple of solutions:
1435 | 
1436 | * You could switch from using HTML5 history API to routing with hashes. If you use React Router, you can switch to `hashHistory` for this effect, but the URL will be longer and more verbose (for example, `http://user.github.io/todomvc/#/todos/42?_k=yknaj`). [Read more](https://github.com/reactjs/react-router/blob/master/docs/guides/Histories.md#histories) about different history implementations in React Router.
1437 | * Alternatively, you can use a trick to teach GitHub Pages to handle 404 by redirecting to your `index.html` page with a special redirect parameter. You would need to add a `404.html` file with the redirection code to the `build` folder before deploying your project, and you’ll need to add code handling the redirect parameter to `index.html`. You can find a detailed explanation of this technique [in this guide](https://github.com/rafrex/spa-github-pages).
1438 | 
1439 | ### Heroku
1440 | 
1441 | Use the [Heroku Buildpack for Create React App](https://github.com/mars/create-react-app-buildpack).<br>
1442 | You can find instructions in [Deploying React with Zero Configuration](https://blog.heroku.com/deploying-react-with-zero-configuration).
1443 | 
1444 | #### Resolving Heroku Deployment Errors
1445 | 
1446 | Sometimes `npm run build` works locally but fails during deploy via Heroku. Following are the most common cases.
1447 | 
1448 | ##### "Module not found: Error: Cannot resolve 'file' or 'directory'"
1449 | 
1450 | If you get something like this:
1451 | 
1452 | ```
1453 | remote: Failed to create a production build. Reason:
1454 | remote: Module not found: Error: Cannot resolve 'file' or 'directory'
1455 | MyDirectory in /tmp/build_1234/src
1456 | ```
1457 | 
1458 | It means you need to ensure that the lettercase of the file or directory you `import` matches the one you see on your filesystem or on GitHub.
1459 | 
1460 | This is important because Linux (the operating system used by Heroku) is case sensitive. So `MyDirectory` and `mydirectory` are two distinct directories and thus, even though the project builds locally, the difference in case breaks the `import` statements on Heroku remotes.
1461 | 
1462 | ##### "Could not find a required file."
1463 | 
1464 | If you exclude or ignore necessary files from the package you will see a error similar this one:
1465 | 
1466 | ```
1467 | remote: Could not find a required file.
1468 | remote:   Name: `index.html`
1469 | remote:   Searched in: /tmp/build_a2875fc163b209225122d68916f1d4df/public
1470 | remote:
1471 | remote: npm ERR! Linux 3.13.0-105-generic
1472 | remote: npm ERR! argv "/tmp/build_a2875fc163b209225122d68916f1d4df/.heroku/node/bin/node" "/tmp/build_a2875fc163b209225122d68916f1d4df/.heroku/node/bin/npm" "run" "build"
1473 | ```
1474 | 
1475 | In this case, ensure that the file is there with the proper lettercase and that’s not ignored on your local `.gitignore` or `~/.gitignore_global`.
1476 | 
1477 | ### Modulus
1478 | 
1479 | See the [Modulus blog post](http://blog.modulus.io/deploying-react-apps-on-modulus) on how to deploy your react app to Modulus.
1480 | 
1481 | ## Netlify
1482 | 
1483 | **To do a manual deploy to Netlify’s CDN:**
1484 | 
1485 | ```sh
1486 | npm install netlify-cli
1487 | netlify deploy
1488 | ```
1489 | 
1490 | Choose `build` as the path to deploy.
1491 | 
1492 | **To setup continuous delivery:**
1493 | 
1494 | With this setup Netlify will build and deploy when you push to git or open a pull request:
1495 | 
1496 | 1. [Start a new netlify project](https://app.netlify.com/signup)
1497 | 2. Pick your Git hosting service and select your repository
1498 | 3. Click `Build your site`
1499 | 
1500 | **Support for client-side routing:**
1501 | 
1502 | To support `pushState`, make sure to create a `public/_redirects` file with the following rewrite rules:
1503 | 
1504 | ```
1505 | /*  /index.html  200
1506 | ```
1507 | 
1508 | When you build the project, Create React App will place the `public` folder contents into the build output.
1509 | 
1510 | ### Now
1511 | 
1512 | [now](https://zeit.co/now) offers a zero-configuration single-command deployment.
1513 | 
1514 | 1. Install the `now` command-line tool either via the recommended [desktop tool](https://zeit.co/download) or via node with `npm install -g now`.
1515 | 
1516 | 2. Install `serve` by running `npm install --save serve`.
1517 | 
1518 | 3. Add this line to `scripts` in `package.json`:
1519 |     
1520 |     ```
1521 |     "now-start": "serve build/",
1522 |     ```
1523 |     
1524 | 4. Run `now` from your project directory. You will see a **now.sh** URL in your output like this:
1525 |     
1526 |     ```
1527 |     > Ready! https://your-project-dirname-tpspyhtdtk.now.sh (copied to clipboard)
1528 |     ```
1529 |     
1530 |     Paste that URL into your browser when the build is complete, and you will see your deployed app.
1531 | 
1532 | Details are available in [this article.](https://zeit.co/blog/now-static)
1533 | 
1534 | ### S3 and CloudFront
1535 | 
1536 | See this [blog post](https://medium.com/@omgwtfmarc/deploying-create-react-app-to-s3-or-cloudfront-48dae4ce0af) on how to deploy your React app to Amazon Web Services [S3](https://aws.amazon.com/s3) and [CloudFront](https://aws.amazon.com/cloudfront/).
1537 | 
1538 | ### Surge
1539 | 
1540 | Install the Surge CLI if you haven’t already by running `npm install -g surge`. Run the `surge` command and log in you or create a new account. You just need to specify the *build* folder and your custom domain, and you are done.
1541 | 
1542 | ```sh
1543 |               email: email@domain.com
1544 |            password: ********
1545 |        project path: /path/to/project/build
1546 |                size: 7 files, 1.8 MB
1547 |              domain: create-react-app.surge.sh
1548 |              upload: [====================] 100%, eta: 0.0s
1549 |    propagate on CDN: [====================] 100%
1550 |                plan: Free
1551 |               users: email@domain.com
1552 |          IP Address: X.X.X.X
1553 | 
1554 |     Success! Project is published and running at create-react-app.surge.sh
1555 | ```
1556 | 
1557 | Note that in order to support routers that use HTML5 `pushState` API, you may want to rename the `index.html` in your build folder to `200.html` before deploying to Surge. This [ensures that every URL falls back to that file](https://surge.sh/help/adding-a-200-page-for-client-side-routing).
1558 | 
1559 | ## Advanced Configuration
1560 | 
1561 | You can adjust various development and production settings by setting environment variables in your shell or with [.env](#adding-development-environment-variables-in-env).
1562 | 
1563 | Variable | Development | Production | Usage
1564 | :--- | :---: | :---: | :---
1565 | BROWSER | :white_check_mark: | :x: | By default, Create React App will open the default system browser, favoring Chrome on macOS. Specify a [browser](https://github.com/sindresorhus/opn#app) to override this behavior, or set it to `none` to disable it completely.
1566 | HOST | :white_check_mark: | :x: | By default, the development web server binds to `localhost`. You may use this variable to specify a different host.
1567 | PORT | :white_check_mark: | :x: | By default, the development web server will attempt to listen on port 3000 or prompt you to attempt the next available port. You may use this variable to specify a different port.
1568 | HTTPS | :white_check_mark: | :x: | When set to `true`, Create React App will run the development server in `https` mode.
1569 | PUBLIC_URL | :x: | :white_check_mark: | Create React App assumes your application is hosted at the serving web server's root or a subpath as specified in [`package.json` (`homepage`)](#building-for-relative-paths). Normally, Create React App ignores the hostname. You may use this variable to force assets to be referenced verbatim to the url you provide (hostname included). This may be particularly useful when using a CDN to host your application.
1570 | CI | :large_orange_diamond: | :white_check_mark: | When set to `true`, Create React App treats warnings as failures in the build. It also makes the test runner non-watching. Most CIs set this flag by default.
1571 | 
1572 | ## Troubleshooting
1573 | 
1574 | ### `npm start` doesn’t detect changes
1575 | 
1576 | When you save a file while `npm start` is running, the browser should refresh with the updated code.<br>
1577 | If this doesn’t happen, try one of the following workarounds:
1578 | 
1579 | * If your project is in a Dropbox folder, try moving it out.
1580 | * If the watcher doesn’t see a file called `index.js` and you’re referencing it by the folder name, you [need to restart the watcher](https://github.com/facebookincubator/create-react-app/issues/1164) due to a Webpack bug.
1581 | * Some editors like Vim and IntelliJ have a “safe write” feature that currently breaks the watcher. You will need to disable it. Follow the instructions in [“Working with editors supporting safe write”](https://webpack.github.io/docs/webpack-dev-server.html#working-with-editors-ides-supporting-safe-write).
1582 | * If your project path contains parentheses, try moving the project to a path without them. This is caused by a [Webpack watcher bug](https://github.com/webpack/watchpack/issues/42).
1583 | * On Linux and macOS, you might need to [tweak system settings](https://webpack.github.io/docs/troubleshooting.html#not-enough-watchers) to allow more watchers.
1584 | * If the project runs inside a virtual machine such as (a Vagrant provisioned) VirtualBox, create an `.env` file in your project directory if it doesn’t exist, and add `CHOKIDAR_USEPOLLING=true` to it. This ensures that the next time you run `npm start`, the watcher uses the polling mode, as necessary inside a VM.
1585 | 
1586 | If none of these solutions help please leave a comment [in this thread](https://github.com/facebookincubator/create-react-app/issues/659).
1587 | 
1588 | ### `npm test` hangs on macOS Sierra
1589 | 
1590 | If you run `npm test` and the console gets stuck after printing `react-scripts test --env=jsdom` to the console there might be a problem with your [Watchman](https://facebook.github.io/watchman/) installation as described in [facebookincubator/create-react-app#713](https://github.com/facebookincubator/create-react-app/issues/713).
1591 | 
1592 | We recommend deleting `node_modules` in your project and running `npm install` (or `yarn` if you use it) first. If it doesn't help, you can try one of the numerous workarounds mentioned in these issues:
1593 | 
1594 | * [facebook/jest#1767](https://github.com/facebook/jest/issues/1767)
1595 | * [facebook/watchman#358](https://github.com/facebook/watchman/issues/358)
1596 | * [ember-cli/ember-cli#6259](https://github.com/ember-cli/ember-cli/issues/6259)
1597 | 
1598 | It is reported that installing Watchman 4.7.0 or newer fixes the issue. If you use [Homebrew](http://brew.sh/), you can run these commands to update it:
1599 | 
1600 | ```
1601 | watchman shutdown-server
1602 | brew update
1603 | brew reinstall watchman
1604 | ```
1605 | 
1606 | You can find [other installation methods](https://facebook.github.io/watchman/docs/install.html#build-install) on the Watchman documentation page.
1607 | 
1608 | If this still doesn’t help, try running `launchctl unload -F ~/Library/LaunchAgents/com.github.facebook.watchman.plist`.
1609 | 
1610 | There are also reports that *uninstalling* Watchman fixes the issue. So if nothing else helps, remove it from your system and try again.
1611 | 
1612 | ### `npm run build` silently fails
1613 | 
1614 | It is reported that `npm run build` can fail on machines with no swap space, which is common in cloud environments. If [the symptoms are matching](https://github.com/facebookincubator/create-react-app/issues/1133#issuecomment-264612171), consider adding some swap space to the machine you’re building on, or build the project locally.
1615 | 
1616 | ### `npm run build` fails on Heroku
1617 | 
1618 | This may be a problem with case sensitive filenames.
1619 | Please refer to [this section](#resolving-heroku-deployment-errors).
1620 | 
1621 | ## Something Missing?
1622 | 
1623 | If you have ideas for more “How To” recipes that should be on this page, [let us know](https://github.com/facebookincubator/create-react-app/issues) or [contribute some!](https://github.com/facebookincubator/create-react-app/edit/master/packages/react-scripts/template/README.md)
1624 | 


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