CedarCopilot/cedar-mail

/**
 * Pure date formatting helpers, split out of ./time.
 *
 * ./time imports chrono-node and fuse.js at module scope for natural-language date parsing. The
 * crm/utils barrel is reachable from `userTasksSlice`, which modules/store/index.ts registers
 * eagerly, so importing a single pure helper from ./time put both NLP libraries on the critical
 * path of every route.
 *
 * Keep this module dependency-free.
 *
 * See docs/design/frontend-load-performance.md §3 F5.
 */
export function toISODateString(date: Date | string | null | undefined): string | undefined {
  if (!date) return undefined;

  // If already a string (from cache), extract date portion
  if (typeof date === 'string') {
    return date.split('T')[0];
  }

  // If it's a Date object (from fresh tRPC response), convert to ISO string
  return date.toISOString().split('T')[0];
}