fix architecture and write new tests

apps/marketplace/src/components/BookingForm.tsx

@@ -131,6 +131,30 @@ const copy = {
   },
 } as const
 
+
+export function calculateBookingTotalDays(startDate: string, endDate: string): number {
+  if (!startDate || !endDate) return 0
+  return Math.max(0, Math.ceil((new Date(endDate).getTime() - new Date(startDate).getTime()) / 86_400_000))
+}
+
+export function resolveReturnLocation({
+  dropoffMode,
+  returnLocation,
+  pickupLocation,
+}: {
+  dropoffMode: 'same' | 'different'
+  returnLocation: string
+  pickupLocation: string
+}): string | undefined {
+  if (dropoffMode === 'different') return returnLocation || undefined
+  return pickupLocation || undefined
+}
+
+export function normalizeOptionalText(value: string): string | undefined {
+  const trimmed = value.trim()
+  return trimmed || undefined
+}
+
 export default function BookingForm({
   vehicleId,
   companySlug,
@@ -169,10 +193,7 @@ export default function BookingForm({
   const [error, setError] = useState<string | null>(null)
   const [success, setSuccess] = useState(false)
 
-  const totalDays =
-    startDate && endDate
-      ? Math.max(0, Math.ceil((new Date(endDate).getTime() - new Date(startDate).getTime()) / 86_400_000))
-      : 0
+  const totalDays = calculateBookingTotalDays(startDate, endDate)
 
   async function handleSubmit(e: React.FormEvent) {
     e.preventDefault()
@@ -228,12 +249,12 @@ export default function BookingForm({
         licenseExpiry: new Date(licenseExpiry).toISOString(),
         licenseCountry: licenseCountry.trim(),
         licenseCategory: licenseCategory.trim(),
-        internationalLicenseNumber: internationalLicenseNumber.trim() || undefined,
+        internationalLicenseNumber: normalizeOptionalText(internationalLicenseNumber),
         startDate: start.toISOString(),
         endDate: end.toISOString(),
         pickupLocation: pickupLocation || undefined,
-        returnLocation: dropoffMode === 'different' ? (returnLocation || undefined) : (pickupLocation || undefined),
-        notes: notes.trim() || undefined,
+        returnLocation: resolveReturnLocation({ dropoffMode, returnLocation, pickupLocation }),
+        notes: normalizeOptionalText(notes),
         language,
       })
       setSuccess(true)