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Webpack boilerplate

webpack-boilerplate

Features

Get Started

Start coding

Note: Also remember to add your own repo to package.json

  "repository": {
    "type": "git",
    "url": "https://github.com/<your-git>/<your-project>.git"
  },

rm -rf .git
git init
git add .
git commit -m "initial commit"

Verify that CSS HMR works

.primary {
  @mixin primary;
}

.primary {
  @mixin primary;
  background-color: red;
}

Verify that JS HMR works

import request from '../../utils/request';

async function determineTime() {
  const moment = await import('moment');
  return moment().format('YYYY-MM-DD HH:mm:ss');
}
const pingServer = (url) => {
  return request(url)
    .then(response => {
      return determineTime()
        .then(time => {
          return `${time}: ${JSON.stringify(response)}`;
        });
    })
    .catch(err => err);
};
export default pingServer;

async function determineTime() {
  const moment = await import('moment');
  return moment().format('HH:mm:ss');
}

Try the bundle

The bundled code is minified and optimized code ready for deployment to your preferred webserver. Before deployment you can verify that the code behaves as expected by running the following npm commands.

Webpack DLL plugin

The Dll Plugin lets you pre-build the parts of your code that don't often change (such as third party library code). Add code that should be built by the Dll plugin to vendor.js. Code built by the the Dll plugin does not utilize tree shaking and is therefore only used for development. For a production build, the same vendor.js file is added as a entry in your webpack project for minification and elimination of dead code.

Lazy loading, System.import()

If you have (large) libraries that is not needed at application startup, you can use lazy loading. Lazy loading (System.import()) is demonstrated in code above.

Polyfills

Add your polyfills to polyfill.js

Running tests

Tests are divided into three categories; unit tests, integration tests and acceptance tests. Unit tests and integration tests uses Moca as a test runner. The acceptance tests uses WebdriverIO as a test runner. Istanbul is used for code coverage and reporting.

Unit tests

The following libraries are used:

To run the unit tests type: npm run test:unit

Integration tests

The following libraries are used:

To run the ingtegration tests type: npm run test:it

Acceptance tests

The following libraries are used:

For now, the (standalone) acceptance tests must be run manually. The only way to ro run standalone acceptance tests on a CI server, is to use a headless browser like PhantomJS (I think). Unfortunatley I have so far had no success running acceptance tests using PhantomJS.

Required steps to run acceptance tests

# yarn, or npm install - just in case
yarn install / npm install

# Make bundle
npm run build:prod

# Fetch actual Seleninum distro
NODE_TLS_REJECT_UNAUTHORIZED=0 ./node_modules/.bin/selenium-standalone install

# Run acceptance tests
npm run wdio

# Expected output

------------------------------------------------------------------
[chrome #0-0] Session ID: e0bf7b24-2bfa-4053-ad47-1e87d5fe409a
[chrome #0-0] Spec: ~/dev/webpack2-boilerplate/test/features/example.feature
[chrome #0-0] Running: chrome
[chrome #0-0]
[chrome #0-0] Title check
[chrome #0-0]
[chrome #0-0]     Get the title of webpage
[chrome #0-0]       ✓ I open the url "http://localhost:8082/"
[chrome #0-0]       ✓ I expect the title of the page to be "Webpack2 Boilerplate"
[chrome #0-0]
[chrome #0-0]     Click the Ping button
[chrome #0-0]       ✓ I open the url "http://localhost:8082/"
[chrome #0-0]       ✓ I click the Ping button
[chrome #0-0]       ✓ I expect the response to be "pong!"
[chrome #0-0]
[chrome #0-0]
[chrome #0-0] 5 passing (5s)

Chromedriver<br/> According to the WebdriverIO Get Stared guide, the Chromedriver standalone server is required for running Chrome browser tests on a local machine. On latest Ubuntu and OSX I have run the tests without installing the Chromedriver. So far I have not experienced any problems running the tests without the Chrome Driver. If you must install Chromedriver, instructions can be found e.g. here, here and here.

Test coverage

npm run build:prod, then browse ./coverage/lcov-report/index.html, ./coverage/unit/lcov-report/index.html, ./coverage/integration/lcov-report/index.html

e2e tests

e2e tests are not implemented in this boilerplate, but basically they are equal to the integration tests. The main difference is that you use a proxy to connect to a "real" api server before running your client api tests. A sample e2e test using a proxy can be found in the ./test/integration/proxy directory.

To see it in action, run the test:proxy-example script.

Hot Module Reloading, HMR

Read Hot Module Replacement - React, React Hot Loader Getting Started, Tree-shaking with webpack 2 and Babel 6 and http://andrewhfarmer.com/webpack-hmr-tutorial/.

How to use the boilerplate with React

The boilerplate may, with a few modifications, be used with React. More details can be found here and here.

Install required packages

# dependencies
yarn add -E react / npm i -S react
yarn add -E react-dom / npm i -S react-dom

# devdependencies
yarn add -D -E babel-preset-react / npm i -D babel-preset-react 
yarn add -D -E react-hot-loader@next / npm i -D react-hot-loader@next
yarn add -D -E eslint-plugin-react / npm i -D eslint-plugin-react

Add React dependencies to src/vendor.js

import 'react';
import 'react-dom';

Modify .babelrc

Add "react" to presets and "react-hot-loader/babel" to development plugins.

{
  "plugins": [
    "syntax-async-functions",
    "syntax-dynamic-import",
    "transform-async-to-generator",
    "transform-regenerator",
    "transform-runtime",
    "transform-class-properties"
  ],
  "presets": [
    ["env", {
      "targets": {
        "browsers": ["last 2 versions", "ie >= 11"]
      }
    }],
    "react",
    "stage-0"
  ],
  "env": {
    "development": {
      "plugins": [
        "react-hot-loader/babel"
      ]
    },
    "test": {
    },
    "production": {
    }
  }
}

Modify .eslintrc

Add "react" to "plugins"

{
  "plugins": [
    "compat",  // Allow configuration of target browser/s (npm i -D eslint-plugin-compat)
    "react"    // React specific linting rules (npm i -D eslint-plugin-react)
  ],
}

Enable all of the rules that you would like to use

{
  "rules": {
    "react/jsx-uses-react": "error",
    "react/jsx-uses-vars": "error",
  }
}

Modify webpack.config.babel.js

entry.app

Add 'react-hot-loader/patch'

app: (!isHot ? [] : [
  './webpack-public-path.js',
  // Put react-hot-loader/patch before webpack-hot-middleware,
  // see: https://github.com/gaearon/react-hot-loader/issues/243
  'react-hot-loader/patch',
  'webpack-hot-middleware/client',
]).concat([
  './styles.scss',
  './index.js'
]),

Create ./src/components/App.js

import React from 'react';

const superStyles = {
  backgroundColor: 'green'
};

const App = () => (
  <div style={superStyles}>
    <h1>Hello React!</h1>
  </div>
);

export default App;

Modify ./src/index.js

import polyfill from './polyfill';
import React from 'react';
import ReactDOM from 'react-dom';
import './config/config';
import logger, {LOG_LEVEL} from './logger/logger';
import App from './components/App';

import './styles.scss';

if(window) {
  /**
   * An event handler for the error event.
   * When an error is thrown, the following arguments are passed to the function:
   * @param msg The message associated with the error, e.g. “Uncaught ReferenceError: foo is not defined”
   * @param url The URL of the script or document associated with the error, e.g. “/dist/app.js”
   * @param lineNo The line number (if available)
   * @param columnNo The column number (if available)
   * @param error The Error object associated with this error (if available)
   * @return {boolean}
   * @see https://developer.mozilla.org/en/docs/Web/API/GlobalEventHandlers/onerror
   * @see https://blog.sentry.io/2016/01/04/client-javascript-reporting-window-onerror.html
   */
  window.onerror = function (msg, url, lineNo, columnNo, error) {
    const err = error || {};
    const detail = {
      name: err.name || msg || '',
      line: lineNo,
      column: columnNo,
      url: url || '',
      stack: err.stack || 'See browser console for detail',
    };

    logger.remoteLogger.log(LOG_LEVEL.error, msg, detail);
    return false;
  };

  /**
   * Flush logger
   */
  window.addEventListener('beforeunload', () => {
    logger.debug('Before unload. Flushing remote logger');
    logger.remoteLogger.flush();
  });
}

const run = () => {
  if (module.hot) {
    // AppContainer is a necessary wrapper component for HMR
    const AppContainer = require('react-hot-loader').AppContainer;
  
    const render = (Component) => {
      ReactDOM.render(
        <AppContainer>
          <Component/>
        </AppContainer>,
        document.getElementById('app')
      );
    };
  
    render(App);
  
    // Hot Module Replacement API
    module.hot.accept('./components/App', () => {
      const NextApp = require('./components/App').default;
      render(NextApp);
    });
  }
  else {
    ReactDOM.render(
      <App/>,
      document.getElementById('app')
    );
  }
};

// Add polyfills
try {
  polyfill()
    .then( () => run()); // Start the app
}
catch(err) {
  console.log('Error loading polyfills:', err); // eslint-disable-line no-console
}

Modify ./src/index.html, e.g.

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>React Webpack</title>
</head>
<body>
<main id="app">

  <!-- Display a message if JS has been disabled on the browser. -->
  <noscript>If you're seeing this message, that means
    <strong>JavaScript has been disabled on your browser</strong>,
    please <strong>enable JS</strong> to make this app work.
  </noscript>

</main>
</body>
</html>

Start coding React

Enjoy your React coding :-)

Complete react-webpack-bolierplate example code can be found here

NPM Scripts