Refactor digit provider

providers/digit/digit.go

@@ -5,13 +5,15 @@ import (
 	"time"
 )
 
+var rng = rand.New(rand.NewSource(time.Now().UnixNano()))
+
 // faNums contains Persian digits.
 var faNums = []string{"۰", "۱", "۲", "۳", "۴", "۵", "۶", "۷", "۸", "۹"}
 
-// PersianDigit returns a random Persian digit.
-func PersianDigit() string {
-	src := rand.NewSource(time.Now().UnixNano())
-	rng := rand.New(src)
+type Digit struct {
+}
 
+// GeneratePersianDigit returns a random Persian digit.
+func (Digit) GeneratePersianDigit() string {
 	return faNums[rng.Intn(len(faNums))]
 }

providers/digit/digit_test.go

@@ -4,9 +4,10 @@ import (
 	"testing"
 )
 
-// TestPersianDigit checks if the digit returned by PersianDigit is one of the valid Persian digits.
-func TestPersianDigit(t *testing.T) {
-	digit := PersianDigit()
+// TestGeneratePersianDigit checks if the digit returned by GeneratePersianDigit is one of the valid Persian digits.
+func TestGeneratePersianDigit(t *testing.T) {
+	d := &Digit{}
+	digit := d.GeneratePersianDigit()
 	found := false
 	for _, d := range faNums {
 		if d == digit {
@@ -15,6 +16,6 @@ func TestPersianDigit(t *testing.T) {
 		}
 	}
 	if !found {
-		t.Errorf("PersianDigit returned an invalid digit: %s", digit)
+		t.Errorf("GeneratePersianDigit returned an invalid digit: %s", digit)
 	}
 }