Jest test async await functions

JavaScript
1

I tried a lot of ways but i failed to know a way to run jest tests on code like that

const geoNamesData = async (url, destination, api) => {
  const response = await fetch(url + destination + api);
  try {
    const data = await response.json();
    //console.log(data.geonames[0]);
    return data.geonames[0];
  } catch (error) {
    console.error(error);
  }
};

export default geoNamesData;

or just simple function expression like that
here i try to run this code but it always failed

import {daysRemaining } from './daysRemaining'

describe('the function "daysRemaining" should exist' , () => {

  test('It should return true', () => {

      expect(daysRemaining).toBeDefined();

  });

});

describe('the function "daysRemaining()" should be a function' , () => {

  test('It should be a function', () => {

      expect(typeof daysRemaining).toBe("function");

  });

});

and my javascript code is

export default function daysRemaining() {

  const today = new Date(); //today date

  const tripDate = new Date(document.getElementById('date').value); //trip date entered by user

  if (tripDate > today) {

    const isRemaining = Math.ceil(

      Math.abs(tripDate - today) / (1000 * 60 * 60 * 24)

    );

    //console.log(isRemaining);

    return !!isRemaining;

  }

  return false;

}

so please how could I run jest tests on functions like previous one