function alphabetSubsequence(str) {
    //  write code here.
    let a =[...str] //convert str to arr to feed to set func
    let b = new Set(a) //removes duplicates
    //checks if the size of set and size of original string are same if not that means it has duplicate
    if(a.length === b.size){ 
        //console.log(a)
        for (let i=1; i < a.length; i++){
            // first do negative check if not there that means its positve
            if(a[i].charCodeAt(0) < a[i-1].charCodeAt(0)){
                console.log(a[i].charCodeAt(0))
                console.log(a[i-1].charCodeAt(0))
                return false
            }
        }
        return true
    }
    else {
        return false
    }
    
}

/**
* 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 false when no duplicates and is  NOT in ascending a - z order ', () => {
        // arrange
        const str = 'hjoi';
        
        // act
        const result = alphabetSubsequence(str);

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