fab-manager/app/frontend/src/javascript/lib/product.ts

import { ProductCategory } from '../models/product-category';

export default class ProductLib {
  /**
   * Map product categories by position
   * @param categories unsorted categories, as returned by the API
   */
  sortCategories = (categories: Array<ProductCategory>): Array<ProductCategory> => {
    const sortedCategories = categories
      .filter(c => !c.parent_id)
      .sort((a, b) => a.position - b.position);
    const childrenCategories = categories
      .filter(c => typeof c.parent_id === 'number')
      .sort((a, b) => b.position - a.position);
    childrenCategories.forEach(c => {
      const parentIndex = sortedCategories.findIndex(i => i.id === c.parent_id);
      sortedCategories.splice(parentIndex + 1, 0, c);
    });
    return sortedCategories;
  };
}