test-params.js

export default function transformParams(source) {
  if (source) {
    const params = Object.entries(source);
    const paramsList = [];

    params.forEach((item) => {
      const key = encodeURIComponent(item[0]);
      const value = encodeURIComponent(item[1]);

      paramsList.push(`${key}=${value}`);
    });

    return paramsList.length ? `?${paramsList.join('&')}` : '';
  }

  return '';
}