Incomplete solution

Hi All

So Ive tried to come up with my own solution different to the example given, which is falling flat somewhere, but I thought that I had everything covered. Can someone point out what is wrong the code below?

Describe your issue in detail here.

  **Your code so far**

function nextInLine(arr, item) {
// Only change code below this line
const removed = testArr[0]
testArr.push(item);
testArr.shift();
return removed;
// Only change code above this line
}

// Setup
const testArr = [1, 2, 3, 4, 5];

// Display code
console.log("Before: " + JSON.stringify(testArr));
console.log(nextInLine(testArr, 6));
console.log("After: " + JSON.stringify(testArr));
  **Your browser information:**

User Agent is: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/100.0.4896.127 Safari/537.36

Challenge: Stand in Line

Link to the challenge:

Which array are you modifying here?