Function interleave

client/src/components/helpers/interleave.ts:7–19

(
  items: T[],
  separator: (index: number) => T
)

 * @returns An array with separators inserted between items
 */
export function interleave<T>(
  items: T[],
  separator: (index: number) => T
): T[] {
  const result: T[] = [];
  items.forEach((item, index) => {
    result.push(item);
    if (index < items.length - 1) {
      result.push(separator(index));
    }
  });
  return result;
}