Add test and fix for #5692 (#7455)

In Calendar, selecting an unavailable date with keyboard selected the
previous available date. Now it does not change the selection.

Co-authored-by: Richard Bann <richard.bann@galaktika.solutions>
Co-authored-by: Yihui Liao <44729383+yihuiliao@users.noreply.github.com>

Author: 3 people

packages/@react-stately/calendar/src/useCalendarState.ts

@@ -291,7 +291,9 @@ export function useCalendarState<T extends DateValue = DateValue>(props: Calenda
       }
     },
     selectFocusedDate() {
-      setValue(focusedDate);
+      if (!(isDateUnavailable && isDateUnavailable(focusedDate))) {
+        setValue(focusedDate);
+      }
     },
     selectDate(date) {
       setValue(date);

packages/react-aria-components/test/Calendar.test.js

@@ -342,4 +342,12 @@ describe('Calendar', () => {
     expect(cell).not.toHaveAttribute('data-selected');
     expect(cell).not.toHaveClass('selected');
   });
+
+  it('should not modify selection when trying to select an unavailable date by keyboard', async () => {
+    let calendar = renderCalendar({isDateUnavailable: d => d.day === 15});
+    let day16 = calendar.getByText('16');
+    fireEvent.click(day16);
+    await user.keyboard('[ArrowLeft][Enter]');
+    expect(calendar.getByLabelText(/selected/)).toBe(day16);
+  });
 });