chore: merge backend repo history into monorepo at backend/

git-subtree-dir: backend
git-subtree-mainline: dc11190527
git-subtree-split: acae976622

backend/internal/utils/age_test.go

@@ -0,0 +1,26 @@
+package utils
+
+import (
+	"testing"
+	"time"
+)
+
+func TestCalcAge_NilBirthDate(t *testing.T) {
+	if age := CalcAge(nil); age != 0 {
+		t.Fatalf("expected 0 for nil birth date, got %d", age)
+	}
+}
+
+func TestCalcAge_BirthdayAlreadyPassedThisYear(t *testing.T) {
+	birth := time.Now().AddDate(-25, -1, 0) // ۲۵ سال و ۱ ماه پیش -> تولد امسال رد شده
+	if age := CalcAge(&birth); age != 25 {
+		t.Fatalf("expected age 25, got %d", age)
+	}
+}
+
+func TestCalcAge_BirthdayNotYetThisYear(t *testing.T) {
+	birth := time.Now().AddDate(-25, 1, 0) // تولد ۱ ماه دیگه‌ست -> هنوز ۲۴ سالشه
+	if age := CalcAge(&birth); age != 24 {
+		t.Fatalf("expected age 24, got %d", age)
+	}
+}