package utils

import "testing"

func TestHaversineKM_SamePoint(t *testing.T) {
	d := HaversineKM(35.6892, 51.3890, 35.6892, 51.3890)
	if d > 0.001 {
		t.Fatalf("expected ~0km for identical points, got %v", d)
	}
}

func TestHaversineKM_TehranToIsfahan(t *testing.T) {
	// فاصله‌ی تهران تا اصفهان تقریباً ۳۴۰ کیلومتره (خط مستقیم)
	d := HaversineKM(35.6892, 51.3890, 32.6546, 51.6680)
	if d < 300 || d > 380 {
		t.Fatalf("expected ~340km between Tehran and Isfahan, got %v", d)
	}
}