Reverse string function in GO (study purpose)

str.go

package str

func Reverse(input string) string {
  rune_array := []rune(input)
  size := len(rune_array) - 1
  result := make([]rune, size + 1)

  for i := 0; i <= size; i++ {
    result[size - i] = rune_array[i]
  }

  return string(result)
}

str_test.go

package str

import (
  "testing"
)

func AssertEqual(t *testing.T, output string, expected string) {
	if output != expected {
		t.Errorf("Expected %s, got %s", expected, output)
	}
}

func TestReverse(t *testing.T) {
  AssertEqual(t, Reverse("AB"),    "BA")
  AssertEqual(t, Reverse("casa"),  "asac")
  AssertEqual(t, Reverse("roma"),  "amor")
  AssertEqual(t, Reverse("Tulio"), "oiluT")
  AssertEqual(t, Reverse("世界"),   "界世")
}