Get function from test file

unit-testing
#1

hi
in my file.test.js

 it('return one event function', () => {
    fetchUrlData('2020-08-17', this );
  });

i wish to acces function in app.js

async function fetchUrlData(todayFormat, jovo) {
    const dateStart = todayFormat;
    const dateEnd = todayFormat;
    const url = 'https://localhost:3000';
    const response = await HttpService.get(url);
    if (response.status === 200) {
       jovo.$session.$data.sapEvent = response.data;
    }
}

how is possible to send this as argument inside test call ?