Read URL (transform stream -> promise)

readUrl.ts

private readUrl(url: string): Promise < string > {
  return new Promise((resolve, reject) => {
    https.get(url, (response) => {
      response.setEncoding('utf8');
      let body = '';
      response.on('data', (data) => {
        body += data;
      });
      response.on('end', () => {
        resolve(body);
      });
      response.on('error', (error) => {
        reject(error);
      });
    });
  });
}