Write SVG to file in Javascript

SVGWriterTest.js

let centerX = 15
let centerY = 15
let radius = 10
let style = "fill:rgb(200,200,255);"

const fs = require('fs')

let svg = ""
svg += '<?xml version="1.0" encoding="UTF-8" standalone="no"?>\n'
svg += '<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">\n'
svg += '<svg width="100%" height="100%" xmlns="http://www.w3.org/2000/svg">\n'

for (let x = 0; x < 12; x++) {
    svg += `\t<circle cx="${centerX+(x*((radius*2)+5))}" cy="${centerY}" r="${radius}" style="${style}"/>\n`
}


svg += '</svg>'

fs.writeFile('testSVG.svg', svg, (err) => {  
    // throws an error, you could also catch it here
    if (err) throw err;

    // success case, the file was saved
    console.log('SVG written!');
});