fix: period picker

Author: stampaaaron

apps/frontend/src/components/questionnaire/PeriodForm.tsx

@@ -26,7 +26,11 @@ export function PeriodForm({ onSave, actionLabel, period }: PeriodFormProps) {
 
   const f = useForm<PeriodFormValues>({
     initialValues: period,
-    onValuesChange({ range: [newStart, newEnd] }, { range: [prevStart, prevEnd] }) {
+    mode: "uncontrolled",
+    onValuesChange(newValues, prevValues) {
+      const [newStart, newEnd] = newValues.range ?? [];
+      const [prevStart, prevEnd] = prevValues.range ?? [];
+
       if ((!prevStart || !prevEnd) && newStart && newEnd) {
         f.setFieldValue("title", t.defaultTitle({ start: formatDate(newStart, "M/YY"), end: formatDate(newEnd, "M/YY") }));
       }

libs/ui/src/components/MonthPicker.tsx

@@ -19,7 +19,7 @@ export function MonthPicker<Type extends DatePickerType = "default">({ selectEnd
   const onChange: MonthPickerProps<Type>["onChange"] = (date) => {
     if (rest.type === "range" && isRangeValue(date) && selectEndOfMonth) {
       const [start, end] = date;
-      const newDate = [start, dayjs(end).utc().endOf("month").toDate()];
+      const newDate = [start, end ? dayjs(end).utc().endOf("month").toDate() : undefined];
       date = newDate as typeof date;
     }
     rest.onChange!(date);