fix: do not delete last schedule (#10444)

Co-authored-by: rkreddy99 <rreddy@e2clouds.com>

packages/trpc/server/routers/viewer/availability/schedule/delete.handler.ts

@@ -26,6 +26,8 @@ export const deleteHandler = async ({ input, ctx }: DeleteOptions) => {
 
   if (scheduleToDelete?.userId !== user.id) throw new TRPCError({ code: "UNAUTHORIZED" });
 
+  // cannot remove this schedule if this is the last schedule remaining
+  // if this is the last remaining schedule of the user then this would be the default schedule and so cannot remove it
   if (user.defaultScheduleId === input.scheduleId) {
     // set a new default or unset default if no other schedule
     const scheduleToSetAsDefault = await prisma.schedule.findFirst({
@@ -40,6 +42,9 @@ export const deleteHandler = async ({ input, ctx }: DeleteOptions) => {
       },
     });
 
+    // to throw the error if there arent any other schedules
+    if (!scheduleToSetAsDefault) throw new TRPCError({ code: "BAD_REQUEST" });
+
     await prisma.user.update({
       where: {
         id: user.id,