function alphabetSubsequence(str) {
    const splitStr = str.split('')
    const nonDupStr = [...new Set(splitStr)];
    
    if (splitStr.length !== nonDupStr.length) {
        return false;
    } else {
        return true;
    } 
}

// function alphabetSubsequenceUsingForLoop(str) {
//     const splitStr = str.split('')
//     let result
    
//      splitStr.forEach((val,index) => {
//          console.log(val.charCode())
//         if (val < splitStr[index+1] && val !== splitStr[index+1]) {
//             result = true
//         } else {
//             result = false 
//             return 
//         }
//     })
    
//     return result
// }



/**
* Test Suite 
*/
describe('alphabetSubsequence()', () => {
    it('returns false when it has duplicate letters', () => {
        // arrange
        const str = 'effg';
        
        // act
        const result = alphabetSubsequence(str);

        // log
        console.log("result 1: ", result);
        
        // assert
        expect(result).toBe(false);
    });

    it('returns false when NOT in ascending a - z order', () => {
        // arrange
        const str = 'cdce';
        
        // act
        const result = alphabetSubsequence(str);

        // log
        console.log("result 2: ", result);
        
        // assert
        expect(result).toBe(false);
    });
    
    it('returns true whenno duplicates and is ascending a - z order ', () => {
        // arrange
        const str = 'ace';
        
        // act
        const result = alphabetSubsequence(str);

        // log
        console.log("result 3: ", result);
        
        // assert
        expect(result).toBe(true);
    });
    
    it('returns true when no duplicates and is mixed a - z order ', () => {
        // arrange
        const str = 'cae';
        
        // act
        const result = alphabetSubsequence(str);

        // log
        console.log("result 4: ", result);
        
        // assert
        expect(result).toBe(true);
    });
});