quick sort implementation in Golang

qsort.go

package qsort

import "math/rand"

func QuickSort(slice []int) []int {
	length := len(slice)

	if length <= 1 {
		sliceCopy := make([]int, length)
		copy(sliceCopy, slice)
		return sliceCopy
	}

	m := slice[rand.Intn(length)]

	less := make([]int, 0, length)
	middle := make([]int, 0, length)
	more := make([]int, 0, length)

	for _, item := range slice {
		switch {
		case item < m:
			less = append(less, item)
		case item == m:
			middle = append(middle, item)
		case item > m:
			more = append(more, item)
		}
	}

	less, more = QuickSort(less), QuickSort(more)

	less = append(less, middle...)
	less = append(less, more...)

	return less
}

qsort_test.go

package qsort

import (
	"reflect"
	"testing"
)

var testData = []struct {
	input          []int
	expectedOutput []int
}{
	{[]int{}, []int{}},
	{[]int{42}, []int{42}},
	{[]int{42, 23}, []int{23, 42}},
	{[]int{23, 42, 32, 64, 12, 4}, []int{4, 12, 23, 32, 42, 64}},
}

func TestQuickSort(t *testing.T) {
	for _, testCase := range testData {
		actual := QuickSort(testCase.input)
		expected := testCase.expectedOutput

		if !reflect.DeepEqual(actual, expected) {
			t.Errorf("%v != %v\n", actual, expected)
		}
	}
}