export type TGetUniqueByArgs = Parameters<typeof getUniqueBy>;
export type TGetUniqueByReturn = ReturnType<typeof getUniqueBy>;
/**
 * Returns the first item for every unique selector result.
 * @template T,TKey
 * @param {T[]} arr Source array
 * @param {(value: T, index: number, array: T[]) => TKey} getKey Unique key selector
 * @returns {T[]} New array containing unique items
 * @throws {TypeError} getUniqueBy: arr must be an array
 * @throws {TypeError} getUniqueBy: getKey must be a function
 * @example
 * getUniqueBy([ { id: 1 }, { id: 1 }, { id: 2 } ], (item) => item.id);
 * @example
 * // Remove duplicate products by SKU while preserving the first result
 * const uniqueProducts = getUniqueBy(products, (product) => product.sku);
 */
export declare const getUniqueBy: <T, TKey>(arr: T[], getKey: (value: T, index: number, array: T[]) => TKey) => T[];