Initial commit of code example files

.gitignore

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+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# Runtime data
+pids
+*.pid
+*.seed
+*.pid.lock
+
+# Directory for instrumented libs generated by jscoverage/JSCover
+lib-cov
+
+# Coverage directory used by tools like istanbul
+coverage
+
+# nyc test coverage
+.nyc_output
+
+# Grunt intermediate storage (http://gruntjs.com/creating-plugins#storing-task-files)
+.grunt
+
+# Bower dependency directory (https://bower.io/)
+bower_components
+
+# node-waf configuration
+.lock-wscript
+
+# Compiled binary addons (https://nodejs.org/api/addons.html)
+build/Release
+
+# Dependency directories
+node_modules/
+jspm_packages/
+
+# TypeScript v1 declaration files
+typings/
+
+# Optional npm cache directory
+.npm
+
+# Optional eslint cache
+.eslintcache
+
+# Optional REPL history
+.node_repl_history
+
+# Output of 'npm pack'
+*.tgz
+
+# Yarn Integrity file
+.yarn-integrity
+
+# dotenv environment variables file
+.env
+
+# next.js build output
+.next
+
+# Mac autogenerated folder information (file color/position/etc)
+.DS_Store
+
+# Snapshots
+src/__snapshots__/*
+
+# VS Code user settings
+.vscode/

README.md

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+**Instructions to reproduce the eror**
+---
+
+#### Preparation
+
+Set `node` environment to `20.11.0`, or use `nvm` to run `nvm use 20.11.0`
+
+#### Steps
+
+1. Clone the repo
+2. Run `yarn install`
+3. Run `yarn test`
+
+#### Expected behavior
+
+All tests should pass.
+
+#### Actual behavior
+
+```
+ReferenceError: TextEncoder is not defined
+
+> 1 | import { configure } from 'enzyme';
+    | ^
+  2 | import Adapter from '@wojtekmaj/enzyme-adapter-react-17';
+  3 |
+  4 | const crypto = require('crypto');
+
+  at Object.<anonymous> (node_modules/undici/lib/web/fetch/data-url.js:5:17)
+  at Object.<anonymous> (node_modules/undici/lib/web/fetch/util.js:7:97)
+  at Object.<anonymous> (node_modules/undici/lib/web/fetch/headers.js:11:5)
+  at Object.<anonymous> (node_modules/undici/lib/web/fetch/response.js:3:90)
+  at Object.<anonymous> (node_modules/undici/lib/web/fetch/index.js:11:5)
+  at Object.<anonymous> (node_modules/undici/index.js:106:19)
+  at Object.<anonymous> (node_modules/cheerio/src/index.ts:24:1)
+  at Object.<anonymous> (node_modules/enzyme/src/Utils.js:9:1)
+  at Object.<anonymous> (node_modules/enzyme/src/ReactWrapper.js:4:1)
+  at Object.<anonymous> (node_modules/enzyme/src/index.js:1:1)
+  at Object.<anonymous> (src/setupTests.js:1:1)
+  at TestScheduler.scheduleTests (node_modules/@jest/core/build/TestScheduler.js:333:13)
+  at runJest (node_modules/@jest/core/build/runJest.js:404:19)
+```

package.json

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+{
+  "name": "code-example",
+  "version": "0.1.0",
+  "private": true,
+  "dependencies": {
+    "crypto": "^1.0.1",
+    "react": "17.0.1",
+    "react-dom": "17.0.1",
+    "react-router-dom": "^5.1.2",
+    "react-scripts": "5.0.1"
+  },
+  "scripts": {
+    "start": "react-scripts start",
+    "build": "react-scripts build",
+    "test": "react-scripts test",
+    "eject": "react-scripts eject"
+  },
+  "browserslist": [
+    ">0.2%",
+    "not dead",
+    "not ie <= 11",
+    "not op_mini all"
+  ],
+  "devDependencies": {
+    "@babel/plugin-proposal-private-property-in-object": "^7.21.11",
+    "@wojtekmaj/enzyme-adapter-react-17": "0.8.0",
+    "enzyme": "3.11.0"
+  }
+}

src/App/__test__/app.test.jsx

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+import React from 'react';
+import { shallow, mount } from 'enzyme';
+import App from '../app';
+
+describe('<App />', () => {
+  let component;
+
+  beforeEach(() => {
+    component = shallow(<App />);
+  });
+
+  test('It should mount', () => {
+    expect(component.length).toBe(1);
+  });
+
+  test('It should contain 2 routes', () => {
+    expect(component.find('Route').length).toBe(2);
+  });
+});

src/App/app.jsx

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+import React from 'react';
+import { Router, Route, Switch, Link } from 'react-router-dom';
+
+function App() {
+  return (
+      <Router>
+        <div className="App container">
+          <div className="row justify-content-center">
+            <Switch>
+              <Route
+                path="/"
+                exact
+                component={LandingPage}
+              />
+              <Route
+                path="/details"
+                component={DetailsPage}
+              />
+
+            </Switch>
+          </div>
+        </div>
+      </Router>
+  );
+}
+
+export default App;
+
+function LandingPage() {
+  return (
+    <div>
+      <h1>Landing Page</h1>
+      <Link to="/details">Go to Details Page</Link>
+    </div>
+  );
+}
+
+function DetailsPage() {
+  return (
+    <div>
+      <h1>Details Page</h1>
+      <Link to="/">Back</Link>
+    </div>
+  );
+}

src/index.js

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+import React from 'react';
+import { render } from 'react-dom';
+import App from './App/app';
+import * as serviceWorker from './serviceWorker';
+
+render(<App />, document.getElementById('root'));
+
+// If you want your app to work offline and load faster, you can change
+// unregister() to register() below. Note this comes with some pitfalls.
+// Learn more about service workers: http://bit.ly/CRA-PWA
+serviceWorker.unregister();

src/serviceWorker.js

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+// This optional code is used to register a service worker.
+// register() is not called by default.
+
+// This lets the app load faster on subsequent visits in production, and gives
+// it offline capabilities. However, it also means that developers (and users)
+// will only see deployed updates on subsequent visits to a page, after all the
+// existing tabs open on the page have been closed, since previously cached
+// resources are updated in the background.
+
+// To learn more about the benefits of this model and instructions on how to
+// opt-in, read http://bit.ly/CRA-PWA.
+
+const isLocalhost = Boolean(
+  window.location.hostname === 'localhost' ||
+    // [::1] is the IPv6 localhost address.
+    window.location.hostname === '[::1]' ||
+    // 127.0.0.1/8 is considered localhost for IPv4.
+    window.location.hostname.match(
+      /^127(?:\.(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}$/
+    )
+);
+
+export function register(config) {
+  if (process.env.NODE_ENV === 'production' && 'serviceWorker' in navigator) {
+    // The URL constructor is available in all browsers that support SW.
+    const publicUrl = new URL(process.env.PUBLIC_URL, window.location);
+    if (publicUrl.origin !== window.location.origin) {
+      // Our service worker won't work if PUBLIC_URL is on a different origin
+      // from what our page is served on. This might happen if a CDN is used to
+      // serve assets; see https://github.com/facebook/create-react-app/issues/2374
+      return;
+    }
+
+    window.addEventListener('load', () => {
+      const swUrl = `${process.env.PUBLIC_URL}/service-worker.js`;
+
+      if (isLocalhost) {
+        // This is running on localhost. Let's check if a service worker still exists or not.
+        checkValidServiceWorker(swUrl, config);
+
+        // Add some additional logging to localhost, pointing developers to the
+        // service worker/PWA documentation.
+        navigator.serviceWorker.ready.then(() => {
+          console.log(
+            'This web app is being served cache-first by a service ' +
+              'worker. To learn more, visit http://bit.ly/CRA-PWA'
+          );
+        });
+      } else {
+        // Is not localhost. Just register service worker
+        registerValidSW(swUrl, config);
+      }
+    });
+  }
+}
+
+function registerValidSW(swUrl, config) {
+  navigator.serviceWorker
+    .register(swUrl)
+    .then(registration => {
+      registration.onupdatefound = () => {
+        const installingWorker = registration.installing;
+        installingWorker.onstatechange = () => {
+          if (installingWorker.state === 'installed') {
+            if (navigator.serviceWorker.controller) {
+              // At this point, the updated precached content has been fetched,
+              // but the previous service worker will still serve the older
+              // content until all client tabs are closed.
+              console.log(
+                'New content is available and will be used when all ' +
+                  'tabs for this page are closed. See http://bit.ly/CRA-PWA.'
+              );
+
+              // Execute callback
+              if (config && config.onUpdate) {
+                config.onUpdate(registration);
+              }
+            } else {
+              // At this point, everything has been precached.
+              // It's the perfect time to display a
+              // "Content is cached for offline use." message.
+              console.log('Content is cached for offline use.');
+
+              // Execute callback
+              if (config && config.onSuccess) {
+                config.onSuccess(registration);
+              }
+            }
+          }
+        };
+      };
+    })
+    .catch(error => {
+      console.error('Error during service worker registration:', error);
+    });
+}
+
+function checkValidServiceWorker(swUrl, config) {
+  // Check if the service worker can be found. If it can't reload the page.
+  fetch(swUrl)
+    .then(response => {
+      // Ensure service worker exists, and that we really are getting a JS file.
+      if (
+        response.status === 404 ||
+        response.headers.get('content-type').indexOf('javascript') === -1
+      ) {
+        // No service worker found. Probably a different app. Reload the page.
+        navigator.serviceWorker.ready.then(registration => {
+          registration.unregister().then(() => {
+            window.location.reload();
+          });
+        });
+      } else {
+        // Service worker found. Proceed as normal.
+        registerValidSW(swUrl, config);
+      }
+    })
+    .catch(() => {
+      console.log(
+        'No internet connection found. App is running in offline mode.'
+      );
+    });
+}
+
+export function unregister() {
+  if ('serviceWorker' in navigator) {
+    navigator.serviceWorker.ready.then(registration => {
+      registration.unregister();
+    });
+  }
+}

src/setupTests.js

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+import { configure } from 'enzyme';
+import Adapter from '@wojtekmaj/enzyme-adapter-react-17';
+
+const crypto = require('crypto');
+
+configure({ adapter: new Adapter() });
+
+// fix for 'crypto.getRandomValues() not supported' error
+Object.defineProperty(globalThis, 'crypto', {
+  value: {
+    getRandomValues: (arr) => crypto.randomBytes(arr.length),
+  },
+});
+
+// fix for 'unstable_flushDiscreteUpdates: Cannot flush updates when React is already rendering' error
+// when <video> is used in a component
+// (https://github.com/testing-library/react-testing-library/issues/470#issuecomment-761821103)
+Object.defineProperty(HTMLMediaElement.prototype, 'muted', {
+  set: () => {},
+});