plane/apps/space/helpers/issue.helper.ts

import { differenceInCalendarDays } from "date-fns/differenceInCalendarDays";
// plane internal
import { STATE_GROUPS } from "@plane/constants";
import { TStateGroups } from "@plane/types";
// helpers
import { getDate } from "@/helpers/date-time.helper";

/**
 * @description check if the issue due date should be highlighted
 * @param date
 * @param stateGroup
 * @returns boolean
 */
export const shouldHighlightIssueDueDate = (
  date: string | Date | null,
  stateGroup: TStateGroups | undefined
): boolean => {
  if (!date || !stateGroup) return false;
  // if the issue is completed or cancelled, don't highlight the due date
  if ([STATE_GROUPS.completed.key, STATE_GROUPS.cancelled.key].includes(stateGroup)) return false;

  const parsedDate = getDate(date);
  if (!parsedDate) return false;

  const targetDateDistance = differenceInCalendarDays(parsedDate, new Date());

  // if the issue is overdue, highlight the due date
  return targetDateDistance <= 0;
};