function insertDashes(arr) {
    arr = arr.split('')
    for(let i=0;i < arr.length-1; i++){
       if( /[a-zA-Z]/.test(arr[i]) && /[a-zA-Z]/.test(arr[i+1]) ){
           arr[i] = arr[i] + '-'
       }
    }
    return arr.join('')
}



/**
* Test Suite 
*/
describe('insertDashes()', () => {
    it('insert dashes in between chars', () => {
        // arrange
        const value = "aba caba";
        
        // act
        const result = insertDashes(value);

        // log
        console.log("result: ", result);
        
        // assert
        expect(result).toBe("a-b-a c-a-b-a");
    });
});