klz-cables.com/.pnpm-store/v10/files/ae/ca024159f78fd6dfa3000184511786b9e92f7f5863fa717c93a8f15cf59506b9562c0c846ae258d2a75172795ea496ae9750b9838d06e75b650ecacbc28bd1

/**
 * Groups array items into a Map, given a function to produce grouping key.
 */
export function groupBy(list, keyFn) {
  const result = new Map();

  for (const item of list) {
    const key = keyFn(item);
    const group = result.get(key);

    if (group === undefined) {
      result.set(key, [item]);
    } else {
      group.push(item);
    }
  }

  return result;
}