first commit

utils/visibility.ts

@@ -0,0 +1,18 @@
+/** Keep rows on or before the dashboard publish cutoff date (ISO `YYYY-MM-DD`). */
+export function throughVisibleDate<T extends { date: string }>(
+  rows: T[],
+  visibleThrough: string | null | undefined
+): T[] {
+  if (!visibleThrough) return rows;
+  return rows.filter((row) => row.date <= visibleThrough);
+}
+
+/** True when `date` is on or before the publish cutoff (or cutoff is unknown). */
+export function isOnOrBeforeVisibleDate(
+  date: string | null | undefined,
+  visibleThrough: string | null | undefined
+): boolean {
+  if (!date) return false;
+  if (!visibleThrough) return true;
+  return date <= visibleThrough;
+}