How to set a file name using window.open

Question

I\'am trying to download temporary result calculated by JavaScript. Say I have a string str, I want to download a file contains str and named it as

Answer 1

A shorter version of accepted one (for my case had to use unicode)

var link = document.createElement("a");
link.href = 'data:text/csv,' + encodeURIComponent("algún texto");
link.download = "Example.csv";
link.click();