function differentSymbolsNaive(str) {
    if (!str) return 0;
    let currentNum = new Set();
    const strArray = str.split('');
    for (let i = 0; i < strArray.length; i++) {
        currentNum.add(strArray[i]);
    }
    return currentNum.size;
}


/**
* Test Suite 
*/
describe('differentSymbolsNaive()', () => {
    it('returns count of unique characters', () => {
        // arrange
        const str = 'cabca';
        
        // act
        const result = differentSymbolsNaive(str);

        // log
        console.log("result: ", result);
        
        // assert
        expect(result).toBe(3);
    });
});