Add verify swap using pointers

numerical/swap.go

@@ -0,0 +1,15 @@
+package numerical
+
+import "fmt"
+
+func swap(x, y *int) {
+	*x, *y = *y, *x
+}
+
+func main() {
+	x := 3
+	y := 2
+	fmt.Println(x, y)
+	swap(&x, &y)
+	fmt.Println(x, y)
+}

numerical/swap_test.go

@@ -0,0 +1,19 @@
+package numerical
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestSwap(t *testing.T) {
+	x := 5
+	y := 6
+
+	expectedX := 6
+	expectedY := 5
+
+	swap(&x, &y)
+	assert.Equal(t, x, expectedX, "value should be equal")
+	assert.Equal(t, y, expectedY, "value should be equal")
+}