Function popCommonItems

src/utils.js:285–315

(itemsSet, getKey, condition)

 * @returns {string[][]} list of common items
 */
const popCommonItems = (itemsSet, getKey, condition) => {
  /** @type {Map<string, string[]>} */
  const map = new Map();

  for (const item of itemsSet) {
    const key = getKey(item);
    if (key) {
      let list = map.get(key);
      if (list === undefined) {
        /** @type {string[]} */
        list = [];
        map.set(key, list);
      }
      list.push(item);
    }
  }

  /** @type {string[][]} */
  const result = [];

  for (const list of map.values()) {
    if (condition(list)) {
      for (const item of list) {
        itemsSet.delete(item);
      }
      result.push(list);
    }
  }

  return result;
};

/**
 * @param {string[]} itemsArr array of items