/** Similar to lodash groupBy */
export const groupBy = <T, K extends keyof any>(
  list: T[],
  getKey: (item: T) => K,
) =>
  list.reduce(
    (previous, currentItem) => {
      const group = getKey(currentItem);
      if (!previous[group]) {
        return { ...previous, [group]: [currentItem] };
      }
      return { ...previous, [group]: previous[group].concat(currentItem) };
    },
    {} as Record<K, T[]>,
  );