title: TypeError: Cannot assign to read only property | after creating a copy
body: <p>I wan't to copy an array (that is stored in my Redux Toolkit store), re-assign some properties and return it back.</p>
  <p>I noticed that it works like this:</p>
  <pre><code>const copy = JSON.parse(JSON.stringify(options));
  copy[0].last = true;
  </code></pre>
  <p>But I wan't to do it like this but it throws an error:</p>
  <pre><code>const copy = [...options];
  copy[0].last = true;
  </code></pre>
  <p>This error is thrown:</p>
  <blockquote>
  <p>Uncaught TypeError: Cannot assign to read only property 'last' of
  object '#'</p>
  </blockquote>
  <p>Why is <code>JSON.stringify</code> and <code>JSON.parse</code> needed here to make it work?</p>
  <p>The options are defined like this:</p>
  <pre><code>interface Options {
    label: string;
    first: boolean;
    last: boolean;
  }
  
  const options: Options[];
  </code></pre>