<pre class="shiki github-dark shaku"><code>function wrap(arr) { const isNumber = (prop) =&gt; typeof prop === 'string' &amp;&amp; !Number.isNaN(Number(prop)); const normalize = (idx, arrLength) =&gt; idx &gt;= 0 ? idx : idx + arrLength; const assert = (idx) =&gt; { if (idx &lt; 0) { throw new Error('incorrect index'); } } return new Proxy(arr, { get(target, prop, receiver) { if (isNumber(prop)) { prop = normalize(Number(prop), target.length); } return Reflect.get(target, prop, receiver); }, set(target, prop, value, receiver) { if (isNumber(prop)) { prop = normalize(Number(prop), target.length); assert(prop); } return Reflect.set(target, prop, value, receiver); } })}</code></pre>

This is my accepted solution

Python supports negative list index , while JavaScript doesn't. Can you write a wrapper function to make negative array index possible? const original…