Method groupItems

lib/help.js:418–434

* Group items by their help group heading. * * @param {Command[] | Option[]} unsortedItems * @param {Command[] | Option[]} visibleItems * @param {Function} getGroup * @returns {Map }

(unsortedItems, visibleItems, getGroup)

   * @returns {Map<string, Command[] | Option[]>}
   */
  groupItems(unsortedItems, visibleItems, getGroup) {
    const result = new Map();
    // Add groups in order of appearance in unsortedItems.
    unsortedItems.forEach((item) => {
      const group = getGroup(item);
      if (!result.has(group)) result.set(group, []);
    });
    // Add items in order of appearance in visibleItems.
    visibleItems.forEach((item) => {
      const group = getGroup(item);
      if (!result.has(group)) {
        result.set(group, []);
      }
      result.get(group).push(item);
    });
    return result;
  }

  /**
   * Generate the built-in help text.