[JavaScript] Asynchronous JavaScript: Promises, Async/Await, and AJAX - Throwing Error Manually

Creating generic function

const getJSON = function (url, errorMsg = 'Something went wrong') {
  return fetch(url).then(response => {
    if (!response.ok) throw new Error(`${errorMsg} (${response.status})`);

    return response.json();
  });
};

Throwing error manually ('Country not found' error)

const getCountryData = function (country) {
  // country 1
  getJSON(`https://restcountries.com/v2/name/${country}`, 'Country not found')
    .then(data => {
      renderCountry(data[0]);
      const neighbor = data[0].borders?.[0]; // optional chaining for no borders


      if (!neighbor) throw new Error('No neighbor found');

      //country 2 (flat chain)
      return getJSON(
        `https://restcountries.com/v2/alpha/${neighbor}`,
        'Country not found'
      );
    })
    .then(data => renderCountry(data, 'neighbor'))
    .catch(err => {
      console.error(`${err} 💥💥💥`);
      renderError(`Something went wrong 💥💥 ${err.message}. Try again!`);
    })
    .finally(() => {
      countriesContainer.style.opacity = 1;
    });
};

btn.addEventListener('click', function () {
  getCountryData('qwlikusn');
});

Throwing error manually ('No neighbor found' error)

const getCountryData = function (country) {
  // country 1
  getJSON(`https://restcountries.com/v2/name/${country}`, 'Country not found')
    .then(data => {
      renderCountry(data[0]);
      const neighbor = data[0].borders?.[0]; // optional chaining for no borders

      if (!neighbor) throw new Error('No neighbor found');

      //country 2 
      return getJSON(
        `https://restcountries.com/v2/alpha/${neighbor}`,
        'Country not found'
      );
    })
    .then(data => renderCountry(data, 'neighbor'))
    .catch(err => {
      console.error(`${err} 💥💥💥`);
      renderError(`Something went wrong 💥💥 ${err.message}. Try again!`);
    })
    .finally(() => {
      countriesContainer.style.opacity = 1;
    });
};

btn.addEventListener('click', function () {
  getCountryData('usa');
});

// no borders
getCountryData('australia');