Quick Sort implementation recursive in Javascript

QuickSort.js

function swap(idxA, idxB, array) {
	const temp = array[idxA]
	array[idxA] = array[idxB]
	array[idxB] = temp
}

// A startIdx will search for elements greather than pivor
// B endIdx will search for elements less than pivor
function quickSortHelper(startIdx, endIdx, array) {
	if (startIdx >= endIdx) return // Remember or EQUAL
	let pivotIdx = startIdx
	let leftIdx = startIdx + 1
	let rightIdx = endIdx
	while (rightIdx >= leftIdx) { // Remember EQUAL
		if (array[leftIdx] > array[pivotIdx] && array[rightIdx] < array[pivotIdx]) {
			swap(leftIdx, rightIdx, array)
		}
		// here is the key part to make sense of the next swap (*)
		if (array[leftIdx] <= array[pivotIdx]) leftIdx++
		if (array[rightIdx] >= array[pivotIdx]) rightIdx--
	}
	// (*)
	swap(pivotIdx, rightIdx, array)
	
	// rightIdx now contains the pivot value and trusted 1th balanced
	const leftSide = rightIdx - 1 - startIdx // 
	const rightSide = endIdx - (rightIdx + 1)
	const isLeftSmaller = leftSide < rightSide
	
	if (isLeftSmaller) {
		quickSortHelper(startIdx, rightIdx - 1, array)
		quickSortHelper(rightIdx + 1, endIdx, array)
	} else {
		quickSortHelper(rightIdx + 1, endIdx, array)
		quickSortHelper(startIdx, rightIdx - 1, array)
	}
}

// Divide an conqueer algorithm
function quickSort(array) {
  quickSortHelper(0, array.length - 1, array)
	return array
}

// Do not edit the line below.
exports.quickSort = quickSort;