├── .gitignore
├── LICENSE
├── README.md
├── package.json
├── public
    ├── favicon.ico
    ├── index.html
    ├── logo192.png
    ├── logo512.png
    ├── manifest.json
    └── robots.txt
├── src
    ├── App.css
    ├── App.js
    ├── App.test.js
    ├── ReactDOMMini.js
    ├── index.css
    ├── index.js
    ├── logo.svg
    └── serviceWorker.js
└── yarn.lock


/.gitignore:
--------------------------------------------------------------------------------
 1 | # See https://help.github.com/articles/ignoring-files/ for more about ignoring files.
 2 | 
 3 | # dependencies
 4 | /node_modules
 5 | /.pnp
 6 | .pnp.js
 7 | 
 8 | # testing
 9 | /coverage
10 | 
11 | # production
12 | /build
13 | 
14 | # misc
15 | .DS_Store
16 | .env.local
17 | .env.development.local
18 | .env.test.local
19 | .env.production.local
20 | 
21 | npm-debug.log*
22 | yarn-debug.log*
23 | yarn-error.log*
24 | 


--------------------------------------------------------------------------------
/LICENSE:
--------------------------------------------------------------------------------
 1 | MIT License
 2 | 
 3 | Copyright (c) Sophie Alpert
 4 | 
 5 | Permission is hereby granted, free of charge, to any person obtaining a copy
 6 | of this software and associated documentation files (the "Software"), to deal
 7 | in the Software without restriction, including without limitation the rights
 8 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 9 | copies of the Software, and to permit persons to whom the Software is
10 | furnished to do so, subject to the following conditions:
11 | 
12 | The above copyright notice and this permission notice shall be included in all
13 | copies or substantial portions of the Software.
14 | 
15 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 | SOFTWARE.
22 | 


--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
 1 | # React DOM Mini
 2 | 
 3 | React DOM Mini is a toy renderer that I built as part of my React Conf 2019 talk, "Building a Custom React Renderer".
 4 | 
 5 | This repo is built with Create React App, and the renderer itself is in [`src/ReactDOMMini.js`](https://github.com/sophiebits/react-dom-mini/blob/master/src/ReactDOMMini.js).
 6 | 
 7 | For more detail, watch the talk online:
 8 | 
 9 | <a href="https://www.youtube.com/watch?v=CGpMlWVcHok" target="_blank"><img src="https://img.youtube.com/vi/CGpMlWVcHok/hqdefault.jpg" height="360"></a>
10 | 


--------------------------------------------------------------------------------
/package.json:
--------------------------------------------------------------------------------
 1 | {
 2 |   "name": "mini-reconciler",
 3 |   "version": "0.1.0",
 4 |   "private": true,
 5 |   "dependencies": {
 6 |     "react": "^16.10.2",
 7 |     "react-dom": "^16.10.2",
 8 |     "react-reconciler": "^0.22.2",
 9 |     "react-scripts": "3.2.0"
10 |   },
11 |   "scripts": {
12 |     "start": "react-scripts start",
13 |     "build": "react-scripts build",
14 |     "test": "react-scripts test",
15 |     "eject": "react-scripts eject"
16 |   },
17 |   "eslintConfig": {
18 |     "extends": "react-app"
19 |   },
20 |   "browserslist": {
21 |     "production": [
22 |       ">0.2%",
23 |       "not dead",
24 |       "not op_mini all"
25 |     ],
26 |     "development": [
27 |       "last 1 chrome version",
28 |       "last 1 firefox version",
29 |       "last 1 safari version"
30 |     ]
31 |   }
32 | }
33 | 


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/public/favicon.ico:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/sophiebits/react-dom-mini/e863db543b33187faefb9d53d05b4bf5409a3ca6/public/favicon.ico


--------------------------------------------------------------------------------
/public/index.html:
--------------------------------------------------------------------------------
 1 | <!DOCTYPE html>
 2 | <html lang="en">
 3 |   <head>
 4 |     <meta charset="utf-8" />
 5 |     <link rel="icon" href="%PUBLIC_URL%/favicon.ico" />
 6 |     <meta name="viewport" content="width=device-width, initial-scale=1" />
 7 |     <meta name="theme-color" content="#000000" />
 8 |     <meta
 9 |       name="description"
10 |       content="Web site created using create-react-app"
11 |     />
12 |     <link rel="apple-touch-icon" href="logo192.png" />
13 |     <!--
14 |       manifest.json provides metadata used when your web app is installed on a
15 |       user's mobile device or desktop. See https://developers.google.com/web/fundamentals/web-app-manifest/
16 |     -->
17 |     <link rel="manifest" href="%PUBLIC_URL%/manifest.json" />
18 |     <!--
19 |       Notice the use of %PUBLIC_URL% in the tags above.
20 |       It will be replaced with the URL of the `public` folder during the build.
21 |       Only files inside the `public` folder can be referenced from the HTML.
22 | 
23 |       Unlike "/favicon.ico" or "favicon.ico", "%PUBLIC_URL%/favicon.ico" will
24 |       work correctly both with client-side routing and a non-root public URL.
25 |       Learn how to configure a non-root public URL by running `npm run build`.
26 |     -->
27 |     <title>React App</title>
28 |   </head>
29 |   <body>
30 |     <noscript>You need to enable JavaScript to run this app.</noscript>
31 |     <div id="root"></div>
32 |     <!--
33 |       This HTML file is a template.
34 |       If you open it directly in the browser, you will see an empty page.
35 | 
36 |       You can add webfonts, meta tags, or analytics to this file.
37 |       The build step will place the bundled scripts into the <body> tag.
38 | 
39 |       To begin the development, run `npm start` or `yarn start`.
40 |       To create a production bundle, use `npm run build` or `yarn build`.
41 |     -->
42 |   </body>
43 | </html>
44 | 


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/public/logo192.png:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/sophiebits/react-dom-mini/e863db543b33187faefb9d53d05b4bf5409a3ca6/public/logo192.png


--------------------------------------------------------------------------------
/public/logo512.png:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/sophiebits/react-dom-mini/e863db543b33187faefb9d53d05b4bf5409a3ca6/public/logo512.png


--------------------------------------------------------------------------------
/public/manifest.json:
--------------------------------------------------------------------------------
 1 | {
 2 |   "short_name": "React App",
 3 |   "name": "Create React App Sample",
 4 |   "icons": [
 5 |     {
 6 |       "src": "favicon.ico",
 7 |       "sizes": "64x64 32x32 24x24 16x16",
 8 |       "type": "image/x-icon"
 9 |     },
10 |     {
11 |       "src": "logo192.png",
12 |       "type": "image/png",
13 |       "sizes": "192x192"
14 |     },
15 |     {
16 |       "src": "logo512.png",
17 |       "type": "image/png",
18 |       "sizes": "512x512"
19 |     }
20 |   ],
21 |   "start_url": ".",
22 |   "display": "standalone",
23 |   "theme_color": "#000000",
24 |   "background_color": "#ffffff"
25 | }
26 | 


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/public/robots.txt:
--------------------------------------------------------------------------------
1 | # https://www.robotstxt.org/robotstxt.html
2 | User-agent: *
3 | 


--------------------------------------------------------------------------------
/src/App.css:
--------------------------------------------------------------------------------
 1 | .App {
 2 |   text-align: center;
 3 | }
 4 | 
 5 | .App-logo {
 6 |   animation: App-logo-spin infinite 20s linear;
 7 |   height: 40vmin;
 8 |   pointer-events: none;
 9 | }
10 | 
11 | .App-header {
12 |   background-color: #282c34;
13 |   min-height: 100vh;
14 |   display: flex;
15 |   flex-direction: column;
16 |   align-items: center;
17 |   justify-content: center;
18 |   font-size: calc(10px + 2vmin);
19 |   color: white;
20 | }
21 | 
22 | .App-link {
23 |   color: #61dafb;
24 | }
25 | 
26 | @keyframes App-logo-spin {
27 |   from {
28 |     transform: rotate(0deg);
29 |   }
30 |   to {
31 |     transform: rotate(360deg);
32 |   }
33 | }
34 | 


--------------------------------------------------------------------------------
/src/App.js:
--------------------------------------------------------------------------------
 1 | import React from 'react';
 2 | import logo from './logo.svg';
 3 | import './App.css';
 4 | 
 5 | function App() {
 6 |   let [showLogo, setShowLogo] = React.useState(true);
 7 | 
 8 |   let [color, setColor] = React.useState('red');
 9 |   React.useEffect(() => {
10 |     let colors = ['red', 'green', 'blue'];
11 |     let i = 0;
12 |     let interval = setInterval(() => {
13 |       i++;
14 |       setColor(colors[i % 3]);
15 |     }, 1000);
16 |     return () => clearInterval(interval);
17 |   }, []);
18 | 
19 |   return (
20 |     <div
21 |       className="App"
22 |       onClick={() => {
23 |         setShowLogo(show => !show);
24 |       }}
25 |     >
26 |       <header className="App-header">
27 |         {showLogo && <img src={logo} className="App-logo" alt="logo" />}
28 |         <p bgColor={color}>
29 |           Edit <code>src/App.js</code> and save to reload.
30 |         </p>
31 |         <a
32 |           className="App-link"
33 |           href="https://reactjs.org"
34 |           target="_blank"
35 |           rel="noopener noreferrer"
36 |         >
37 |           Learn React
38 |         </a>
39 |       </header>
40 |     </div>
41 |   );
42 | }
43 | 
44 | export default App;
45 | 


--------------------------------------------------------------------------------
/src/App.test.js:
--------------------------------------------------------------------------------
 1 | import React from 'react';
 2 | import ReactDOM from 'react-dom';
 3 | import App from './App';
 4 | 
 5 | it('renders without crashing', () => {
 6 |   const div = document.createElement('div');
 7 |   ReactDOM.render(<App />, div);
 8 |   ReactDOM.unmountComponentAtNode(div);
 9 | });
10 | 


--------------------------------------------------------------------------------
/src/ReactDOMMini.js:
--------------------------------------------------------------------------------
  1 | import ReactReconciler from 'react-reconciler';
  2 | 
  3 | let reconciler = ReactReconciler({
  4 |   /* configuration for how to talk to the host environment */
  5 |   /* aka "host config" */
  6 | 
  7 |   supportsMutation: true,
  8 | 
  9 |   createInstance(
 10 |     type,
 11 |     props,
 12 |     rootContainerInstance,
 13 |     hostContext,
 14 |     internalInstanceHandle,
 15 |   ) {
 16 |     let el = document.createElement(type);
 17 |     ['alt', 'className', 'href', 'rel', 'src', 'target'].forEach(k => {
 18 |       if (props[k]) el[k] = props[k];
 19 |     });
 20 | 
 21 |     if (props.onClick) {
 22 |       el.addEventListener('click', props.onClick);
 23 |     }
 24 |     if (props.bgColor) {
 25 |       el.style.backgroundColor = props.bgColor;
 26 |     }
 27 | 
 28 |     return el;
 29 |   },
 30 |   createTextInstance(
 31 |     text,
 32 |     rootContainerInstance,
 33 |     hostContext,
 34 |     internalInstanceHandle,
 35 |   ) {
 36 |     return document.createTextNode(text);
 37 |   },
 38 | 
 39 |   appendChildToContainer(container, child) {
 40 |     container.appendChild(child);
 41 |   },
 42 |   appendChild(parent, child) {
 43 |     parent.appendChild(child);
 44 |   },
 45 |   appendInitialChild(parent, child) {
 46 |     parent.appendChild(child);
 47 |   },
 48 | 
 49 |   removeChildFromContainer(container, child) {
 50 |     container.removeChild(child);
 51 |   },
 52 |   removeChild(parent, child) {
 53 |     parent.removeChild(child);
 54 |   },
 55 |   insertInContainerBefore(container, child, before) {
 56 |     container.insertBefore(child, before);
 57 |   },
 58 |   insertBefore(parent, child, before) {
 59 |     parent.insertBefore(child, before);
 60 |   },
 61 | 
 62 |   prepareUpdate(
 63 |     instance,
 64 |     type,
 65 |     oldProps,
 66 |     newProps,
 67 |     rootContainerInstance,
 68 |     currentHostContext,
 69 |   ) {
 70 |     let payload;
 71 |     if (oldProps.bgColor !== newProps.bgColor) {
 72 |       payload = {newBgColor: newProps.bgColor};
 73 |     }
 74 |     return payload;
 75 |   },
 76 |   commitUpdate(
 77 |     instance,
 78 |     updatePayload,
 79 |     type,
 80 |     oldProps,
 81 |     newProps,
 82 |     finishedWork,
 83 |   ) {
 84 |     if (updatePayload.newBgColor) {
 85 |       instance.style.backgroundColor = updatePayload.newBgColor;
 86 |     }
 87 |   },
 88 | 
 89 |   finalizeInitialChildren() {},
 90 |   getChildHostContext() {},
 91 |   getPublicInstance() {},
 92 |   getRootHostContext() {},
 93 |   prepareForCommit() {},
 94 |   resetAfterCommit() {},
 95 |   shouldSetTextContent() {
 96 |     return false;
 97 |   },
 98 | });
 99 | 
100 | let ReactDOMMini = {
101 |   render(whatToRender, div) {
102 |     let container = reconciler.createContainer(div, false, false);
103 |     reconciler.updateContainer(whatToRender, container, null, null);
104 |   },
105 | };
106 | 
107 | export default ReactDOMMini;


--------------------------------------------------------------------------------
/src/index.css:
--------------------------------------------------------------------------------
 1 | body {
 2 |   margin: 0;
 3 |   font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Roboto", "Oxygen",
 4 |     "Ubuntu", "Cantarell", "Fira Sans", "Droid Sans", "Helvetica Neue",
 5 |     sans-serif;
 6 |   -webkit-font-smoothing: antialiased;
 7 |   -moz-osx-font-smoothing: grayscale;
 8 | }
 9 | 
10 | code {
11 |   font-family: source-code-pro, Menlo, Monaco, Consolas, "Courier New",
12 |     monospace;
13 | }
14 | 


--------------------------------------------------------------------------------
/src/index.js:
--------------------------------------------------------------------------------
 1 | import React from 'react';
 2 | // import ReactDOM from 'react-dom';
 3 | import ReactDOMMini from './ReactDOMMini';
 4 | import './index.css';
 5 | import App from './App';
 6 | import * as serviceWorker from './serviceWorker';
 7 | 
 8 | ReactDOMMini.render(<App />, document.getElementById('root'));
 9 | 
10 | // If you want your app to work offline and load faster, you can change
11 | // unregister() to register() below. Note this comes with some pitfalls.
12 | // Learn more about service workers: https://bit.ly/CRA-PWA
13 | serviceWorker.unregister();
14 | 


--------------------------------------------------------------------------------
/src/logo.svg:
--------------------------------------------------------------------------------
1 | <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 841.9 595.3">
2 |     <g fill="#61DAFB">
3 |         <path d="M666.3 296.5c0-32.5-40.7-63.3-103.1-82.4 14.4-63.6 8-114.2-20.2-130.4-6.5-3.8-14.1-5.6-22.4-5.6v22.3c4.6 0 8.3.9 11.4 2.6 13.6 7.8 19.5 37.5 14.9 75.7-1.1 9.4-2.9 19.3-5.1 29.4-19.6-4.8-41-8.5-63.5-10.9-13.5-18.5-27.5-35.3-41.6-50 32.6-30.3 63.2-46.9 84-46.9V78c-27.5 0-63.5 19.6-99.9 53.6-36.4-33.8-72.4-53.2-99.9-53.2v22.3c20.7 0 51.4 16.5 84 46.6-14 14.7-28 31.4-41.3 49.9-22.6 2.4-44 6.1-63.6 11-2.3-10-4-19.7-5.2-29-4.7-38.2 1.1-67.9 14.6-75.8 3-1.8 6.9-2.6 11.5-2.6V78.5c-8.4 0-16 1.8-22.6 5.6-28.1 16.2-34.4 66.7-19.9 130.1-62.2 19.2-102.7 49.9-102.7 82.3 0 32.5 40.7 63.3 103.1 82.4-14.4 63.6-8 114.2 20.2 130.4 6.5 3.8 14.1 5.6 22.5 5.6 27.5 0 63.5-19.6 99.9-53.6 36.4 33.8 72.4 53.2 99.9 53.2 8.4 0 16-1.8 22.6-5.6 28.1-16.2 34.4-66.7 19.9-130.1 62-19.1 102.5-49.9 102.5-82.3zm-130.2-66.7c-3.7 12.9-8.3 26.2-13.5 39.5-4.1-8-8.4-16-13.1-24-4.6-8-9.5-15.8-14.4-23.4 14.2 2.1 27.9 4.7 41 7.9zm-45.8 106.5c-7.8 13.5-15.8 26.3-24.1 38.2-14.9 1.3-30 2-45.2 2-15.1 0-30.2-.7-45-1.9-8.3-11.9-16.4-24.6-24.2-38-7.6-13.1-14.5-26.4-20.8-39.8 6.2-13.4 13.2-26.8 20.7-39.9 7.8-13.5 15.8-26.3 24.1-38.2 14.9-1.3 30-2 45.2-2 15.1 0 30.2.7 45 1.9 8.3 11.9 16.4 24.6 24.2 38 7.6 13.1 14.5 26.4 20.8 39.8-6.3 13.4-13.2 26.8-20.7 39.9zm32.3-13c5.4 13.4 10 26.8 13.8 39.8-13.1 3.2-26.9 5.9-41.2 8 4.9-7.7 9.8-15.6 14.4-23.7 4.6-8 8.9-16.1 13-24.1zM421.2 430c-9.3-9.6-18.6-20.3-27.8-32 9 .4 18.2.7 27.5.7 9.4 0 18.7-.2 27.8-.7-9 11.7-18.3 22.4-27.5 32zm-74.4-58.9c-14.2-2.1-27.9-4.7-41-7.9 3.7-12.9 8.3-26.2 13.5-39.5 4.1 8 8.4 16 13.1 24 4.7 8 9.5 15.8 14.4 23.4zM420.7 163c9.3 9.6 18.6 20.3 27.8 32-9-.4-18.2-.7-27.5-.7-9.4 0-18.7.2-27.8.7 9-11.7 18.3-22.4 27.5-32zm-74 58.9c-4.9 7.7-9.8 15.6-14.4 23.7-4.6 8-8.9 16-13 24-5.4-13.4-10-26.8-13.8-39.8 13.1-3.1 26.9-5.8 41.2-7.9zm-90.5 125.2c-35.4-15.1-58.3-34.9-58.3-50.6 0-15.7 22.9-35.6 58.3-50.6 8.6-3.7 18-7 27.7-10.1 5.7 19.6 13.2 40 22.5 60.9-9.2 20.8-16.6 41.1-22.2 60.6-9.9-3.1-19.3-6.5-28-10.2zM310 490c-13.6-7.8-19.5-37.5-14.9-75.7 1.1-9.4 2.9-19.3 5.1-29.4 19.6 4.8 41 8.5 63.5 10.9 13.5 18.5 27.5 35.3 41.6 50-32.6 30.3-63.2 46.9-84 46.9-4.5-.1-8.3-1-11.3-2.7zm237.2-76.2c4.7 38.2-1.1 67.9-14.6 75.8-3 1.8-6.9 2.6-11.5 2.6-20.7 0-51.4-16.5-84-46.6 14-14.7 28-31.4 41.3-49.9 22.6-2.4 44-6.1 63.6-11 2.3 10.1 4.1 19.8 5.2 29.1zm38.5-66.7c-8.6 3.7-18 7-27.7 10.1-5.7-19.6-13.2-40-22.5-60.9 9.2-20.8 16.6-41.1 22.2-60.6 9.9 3.1 19.3 6.5 28.1 10.2 35.4 15.1 58.3 34.9 58.3 50.6-.1 15.7-23 35.6-58.4 50.6zM320.8 78.4z"/>
4 |         <circle cx="420.9" cy="296.5" r="45.7"/>
5 |         <path d="M520.5 78.1z"/>
6 |     </g>
7 | </svg>


--------------------------------------------------------------------------------
/src/serviceWorker.js:
--------------------------------------------------------------------------------
  1 | // This optional code is used to register a service worker.
  2 | // register() is not called by default.
  3 | 
  4 | // This lets the app load faster on subsequent visits in production, and gives
  5 | // it offline capabilities. However, it also means that developers (and users)
  6 | // will only see deployed updates on subsequent visits to a page, after all the
  7 | // existing tabs open on the page have been closed, since previously cached
  8 | // resources are updated in the background.
  9 | 
 10 | // To learn more about the benefits of this model and instructions on how to
 11 | // opt-in, read https://bit.ly/CRA-PWA
 12 | 
 13 | const isLocalhost = Boolean(
 14 |   window.location.hostname === 'localhost' ||
 15 |     // [::1] is the IPv6 localhost address.
 16 |     window.location.hostname === '[::1]' ||
 17 |     // 127.0.0.1/8 is considered localhost for IPv4.
 18 |     window.location.hostname.match(
 19 |       /^127(?:\.(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}$/
 20 |     )
 21 | );
 22 | 
 23 | export function register(config) {
 24 |   if (process.env.NODE_ENV === 'production' && 'serviceWorker' in navigator) {
 25 |     // The URL constructor is available in all browsers that support SW.
 26 |     const publicUrl = new URL(process.env.PUBLIC_URL, window.location.href);
 27 |     if (publicUrl.origin !== window.location.origin) {
 28 |       // Our service worker won't work if PUBLIC_URL is on a different origin
 29 |       // from what our page is served on. This might happen if a CDN is used to
 30 |       // serve assets; see https://github.com/facebook/create-react-app/issues/2374
 31 |       return;
 32 |     }
 33 | 
 34 |     window.addEventListener('load', () => {
 35 |       const swUrl = `${process.env.PUBLIC_URL}/service-worker.js`;
 36 | 
 37 |       if (isLocalhost) {
 38 |         // This is running on localhost. Let's check if a service worker still exists or not.
 39 |         checkValidServiceWorker(swUrl, config);
 40 | 
 41 |         // Add some additional logging to localhost, pointing developers to the
 42 |         // service worker/PWA documentation.
 43 |         navigator.serviceWorker.ready.then(() => {
 44 |           console.log(
 45 |             'This web app is being served cache-first by a service ' +
 46 |               'worker. To learn more, visit https://bit.ly/CRA-PWA'
 47 |           );
 48 |         });
 49 |       } else {
 50 |         // Is not localhost. Just register service worker
 51 |         registerValidSW(swUrl, config);
 52 |       }
 53 |     });
 54 |   }
 55 | }
 56 | 
 57 | function registerValidSW(swUrl, config) {
 58 |   navigator.serviceWorker
 59 |     .register(swUrl)
 60 |     .then(registration => {
 61 |       registration.onupdatefound = () => {
 62 |         const installingWorker = registration.installing;
 63 |         if (installingWorker == null) {
 64 |           return;
 65 |         }
 66 |         installingWorker.onstatechange = () => {
 67 |           if (installingWorker.state === 'installed') {
 68 |             if (navigator.serviceWorker.controller) {
 69 |               // At this point, the updated precached content has been fetched,
 70 |               // but the previous service worker will still serve the older
 71 |               // content until all client tabs are closed.
 72 |               console.log(
 73 |                 'New content is available and will be used when all ' +
 74 |                   'tabs for this page are closed. See https://bit.ly/CRA-PWA.'
 75 |               );
 76 | 
 77 |               // Execute callback
 78 |               if (config && config.onUpdate) {
 79 |                 config.onUpdate(registration);
 80 |               }
 81 |             } else {
 82 |               // At this point, everything has been precached.
 83 |               // It's the perfect time to display a
 84 |               // "Content is cached for offline use." message.
 85 |               console.log('Content is cached for offline use.');
 86 | 
 87 |               // Execute callback
 88 |               if (config && config.onSuccess) {
 89 |                 config.onSuccess(registration);
 90 |               }
 91 |             }
 92 |           }
 93 |         };
 94 |       };
 95 |     })
 96 |     .catch(error => {
 97 |       console.error('Error during service worker registration:', error);
 98 |     });
 99 | }
100 | 
101 | function checkValidServiceWorker(swUrl, config) {
102 |   // Check if the service worker can be found. If it can't reload the page.
103 |   fetch(swUrl)
104 |     .then(response => {
105 |       // Ensure service worker exists, and that we really are getting a JS file.
106 |       const contentType = response.headers.get('content-type');
107 |       if (
108 |         response.status === 404 ||
109 |         (contentType != null && contentType.indexOf('javascript') === -1)
110 |       ) {
111 |         // No service worker found. Probably a different app. Reload the page.
112 |         navigator.serviceWorker.ready.then(registration => {
113 |           registration.unregister().then(() => {
114 |             window.location.reload();
115 |           });
116 |         });
117 |       } else {
118 |         // Service worker found. Proceed as normal.
119 |         registerValidSW(swUrl, config);
120 |       }
121 |     })
122 |     .catch(() => {
123 |       console.log(
124 |         'No internet connection found. App is running in offline mode.'
125 |       );
126 |     });
127 | }
128 | 
129 | export function unregister() {
130 |   if ('serviceWorker' in navigator) {
131 |     navigator.serviceWorker.ready.then(registration => {
132 |       registration.unregister();
133 |     });
134 |   }
135 | }
136 | 


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