suppose the object is obj ={foo:"bla,bla2,bla3",bar:"bla,bla5"}
I want to convert it to 'obj={foo:["bla","bla2","bla3"],bar:["bla","bla5"]}'
Don't know why you want to do that, but here you can just loop through obj with a for...in loop and split the strings by commas:
const obj = {foo:"bla,bla2,bla3",bar:"bla,bla5"};
for (name in obj) {
obj[name] = obj[name].split(',');
}
console.log(obj)