Unique function for arrays/slices in Go

How to write a functional Unique function in golang using generics, including a unit test. Quite handy when processing data!

---

Unique returns a new slice containing the unique elements from the input slice.

func Unique[A comparable](input []A) []A {
	seen := make(map[A]bool)
	var result []A
	for _, v := range input {
		if !seen[v] {
			seen[v] = true
			result = append(result, v)
		}
	}
	return result
}

and this is a unittest for the function:

func TestUnique(t *testing.T) {
	input := []int{1, 2, 2, 3, 3, 3, 4, 4, 4, 4}
	expected := []int{1, 2, 3, 4}
	result := util.Unique(input)
	if !reflect.DeepEqual(expected, result) {
		t.Errorf("Expected %v, got %v", expected, result)
	}
}