Javascript special array set operations

arrayFunctions.js

/*
  Return the sets intersection.
  Params
    arrA : array
    arrB : array
  Return
    array
*/
const intersection  = (arrA,arrB) => arrA.filter(x => arrB.includes(x));

/*
  Return the difference of two sets.
  Params
    arrA : array
    arrB : array
  Return
    array
*/
const difference = (arrA,arrB) => arrA.filter(x => !arrB.includes(x));

/*
  Make the simetric difference between two arrays.
  Params
    arrA : array
    arrB : array
  Return
    array
*/
const symDifference = (arrA,arrB) => arrA.filter(x => !arrB.includes(x)).concat(arrB.filter(x => !arrA.includes(x)));

/*
  Return the union between two sets.
  Params
    arrA : array
    arrB : array
  Return
    array
*/
const union = (arrA,arrB) => [...arrA, ...arrB];

/*
  Return the union of two sets handling repetead elements.
  Params
    topic:string,
    msg: {structure}
  Return
    promise
*/
const unionUnique = (arrA,arrB)=> [...new Set([...arrA, ...arrB])];

module.exports = {  
  intersection,
  difference,  
  symDifference,
  union,
  unionUnique
};