Short Long Short.js

/*
DESCRIPTION:
Given 2 strings, a and b, return a string of the form short+long+short, with the shorter string on the outside and the longer string on the inside. The strings will not be the same length, but they may be empty ( zero length ).

Hint for R users:

The length of string is not always the same as the number of characters
For example: (Input1, Input2) --> output

("1", "22") --> "1221"
("22", "1") --> "1221"
*/

// My solution:

function solution(a, b){
    return a.length > b.length ? b + a + b : a + b + a;
  }