title: Object is possibly null. TypeScript error
body: <p>How to fix ESLint error: &quot;Object is possibly null&quot;?
  In my code I'm checking null, but anyway have error</p>
  <pre><code>if (controlInput !== null) {
    if (controlInput.match(/[$;.,'&quot;-=!@#$%^&amp;*()]/g).length !== 0) {
      return 'some message'
    }
  }
  </code></pre>