もちろん、これがコメントとテスト付きの更新されたコードだ：

```
def quick_sort(arr):
    """
    This function implements the quick sort algorithm to sort an input array in ascending order.

    Parameters:
        arr (list): The input list to be sorted

    Returns:
        list: The sorted list

    """
    # Base case: If the input list is empty or contains only one element, return it as is
    if len(arr) <= 1:
        return arr
    else:
        # Choose the first element of the list as the pivot
        pivot = arr[0]

        # Partition the input list into two sub-lists based on the pivot
        left = []
        right = []
        for i in range(1, len(arr)):
            if arr[i] < pivot:
                left.append(arr[i])
            else:
                right.append(arr[i])

        # Recursively apply quick sort to the two sub-lists and concatenate the results
        return quick_sort(left) + [pivot] + quick_sort(right)


# Tests
arr1 = [3, 1, 4, 1, 5, 9, 2, 6, 5, 3, 5]
sorted_arr1 = quick_sort(arr1)
print(sorted_arr1)  # Output: [1, 1, 2, 3, 3, 4, 5, 5, 5, 6, 9]

arr2 = [5, 4, 3, 2, 1]
sorted_arr2 = quick_sort(arr2)
print(sorted_arr2)  # Output: [1, 2, 3, 4, 5]

arr3 = []
sorted_arr3 = quick_sort(arr3)
print(sorted_arr3)  # Output: []

arr4 = [1]
sorted_arr4 = quick_sort(arr4)
print(sorted_arr4)  # Output: [1]

arr5 = [1, 1, 1, 1, 1]
sorted_arr5 = quick_sort(arr5)
print(sorted_arr5)  # Output: [1, 1, 1, 1, 1]

arr6 = [2, 1]
sorted_arr6 = quick_sort(arr6)
print(sorted_arr6)  # Output: [1, 2]
```

テストでは、関数がエッジケースを処理し、それぞれの入力に対して期待される出力を返すことができることをチェックするために、長さと内容が異なるいくつかの入力リストを用意しました。
Sure, here's the updated code with comments and tests:

def quick_sort(arr):
    """
    This function implements the quick sort algorithm to sort an input array in ascending order.

    Parameters:
        arr (list): The input list to be sorted

    Returns:
        list: The sorted list

    """
    # Base case: If the input list is empty or contains only one element, return it as is
    if len(arr) <= 1:
        return arr
    else:
        # Choose the first element of the list as the pivot
        pivot = arr[0]

        # Partition the input list into two sub-lists based on the pivot
        left = []
        right = []
        for i in range(1, len(arr)):
            if arr[i] < pivot:
                left.append(arr[i])
            else:
                right.append(arr[i])

        # Recursively apply quick sort to the two sub-lists and concatenate the results
        return quick_sort(left) + [pivot] + quick_sort(right)


# Tests
arr1 = [3, 1, 4, 1, 5, 9, 2, 6, 5, 3, 5]
sorted_arr1 = quick_sort(arr1)
print(sorted_arr1)  # Output: [1, 1, 2, 3, 3, 4, 5, 5, 5, 6, 9]

arr2 = [5, 4, 3, 2, 1]
sorted_arr2 = quick_sort(arr2)
print(sorted_arr2)  # Output: [1, 2, 3, 4, 5]

arr3 = []
sorted_arr3 = quick_sort(arr3)
print(sorted_arr3)  # Output: []

arr4 = [1]
sorted_arr4 = quick_sort(arr4)
print(sorted_arr4)  # Output: [1]

arr5 = [1, 1, 1, 1, 1]
sorted_arr5 = quick_sort(arr5)
print(sorted_arr5)  # Output: [1, 1, 1, 1, 1]

arr6 = [2, 1]
sorted_arr6 = quick_sort(arr6)
print(sorted_arr6)  # Output: [1, 2]


In the tests, we have included several input lists of varying length and content to check that the function can handle edge cases and return the expected output for each input.