title: React Native: error: bundling failed: index.js: "" is not a valid identifer name
body: <p>I have a React Native app which was running perfectly earlier this morning. I've deleted <code>package-lock.json</code> after mistakenly doing an <code>npm install</code> instead of a <code>yarn install</code>. Then I've ran <code>yarn install</code> and now when I try to run my app I get this error at the packager:</p>
  
  <pre><code>error: bundling failed: index.js: "" is not a valid identifer name
  BUNDLE  [ios, dev] ./index.js ░░░░░░░░░░░░░░░░ 0.0% (0/1), failed.
  </code></pre>
  
  <p>I've also closed packager and Vscode, removed <code>node_modules</code> and tried running <code>yarn install</code> again but I get the same error. I haven't changed a single line in my code and it was working before that.</p>
  
  <p>What is going on?</p>