refactor(SW-649): reusable getDaysInMonth function

components/Forms/Signup/schema.ts

@@ -16,7 +16,9 @@ export const signUpSchema = z.object({
     "Phone is required",
     "Please enter a valid phone number"
   ),
-  dateOfBirth: z.string().min(1),
+  dateOfBirth: z.string().min(1, {
+    message: "Date of birth is required",
+  }),
   address: z.object({
     countryCode: z
       .string({

components/TempDesignSystem/Form/Date/index.tsx

@@ -56,15 +56,20 @@ export default function DateSelect({ name, registerOptions = {} }: DateProps) {
     .reverse()
     .map((year) => ({ value: year, label: year.toString() }))
 
-  const daysInMonth =
-    selectedMonth !== null && selectedYear !== null
-      ? dt(`${selectedYear}-${selectedMonth + 1}-01`).daysInMonth()
-      : 31
+  function getDaysInMonth(year: number | null, month: number | null): number {
+    if (month === null) {
+      return 31
+    }
+    const yearToUse = year ?? new Date().getFullYear()
+    return dt(`${yearToUse}-${month + 1}-01`).daysInMonth()
+  }
 
-  const days = rangeArray(1, daysInMonth).map((day) => ({
-    value: day,
-    label: `${day}`,
-  }))
+  const days = rangeArray(1, getDaysInMonth(selectedYear, selectedMonth)).map(
+    (day) => ({
+      value: day,
+      label: `${day}`,
+    })
+  )
 
   function handleSegmentChange(selector: DateName, value: number) {
     let newYear = selectedYear
@@ -84,7 +89,7 @@ export default function DateSelect({ name, registerOptions = {} }: DateProps) {
         newMonth = value - 1
         setSelectedMonth(newMonth)
         if (selectedDay) {
-          const maxDays = dt(`${newYear}-${value}-01`).daysInMonth()
+          const maxDays = getDaysInMonth(newYear, newMonth)
           if (selectedDay > maxDays) {
             newDay = maxDays
             setSelectedDay(newDay)