title: Create React App (TypeScript) auto-generating react-app-env.d.ts in src directory
body: <h2>Context:</h2>
  
  <p>I just ported one app from <code>create-react-app-typescript</code> to <code>create-react-app</code>. In a identically structured but different app, I did the same steps.</p>
  
  <h2>Steps:</h2>
  
  <pre><code>npm uninstall react-scripts-ts
  npm install react-scripts
  npm install --save typescript @types/node @types/react @types/react-dom @types/jest
  </code></pre>
  
  <p><a href="https://vincenttunru.com/migrate-create-react-app-typescript-to-create-react-app/" rel="noreferrer">Detailed Steps</a></p>
  
  <h2>Problems unique to second app:</h2>
  
  <ul>
  <li>Type error: Cannot compile namespaces when the '--isolatedModules' flag is provided.  TS1208</li>
  <li>Generated file <code>src/react-app-env.d.ts</code></li>
  </ul>
  
  <h2>Assumption:</h2>
  
  <p>The generated file <code>src/react-app-env.d.ts</code> causes the <code>--isolatedModules</code> error.</p>
  
  <h1>Actual Question:</h1>
  
  <p>How do I prevent <code>react-scripts</code> from generating the <code>src/react-app-env.d.ts</code> file upon <code>react-scripts start</code>?</p>