randomise avg ids

randomise-svg-ids.js

const fs = require('fs');
const path = require('path');
const crypto = require('crypto');

const findIdsRegex = /id="(.+?)"?/ig;
const fileName = process.argv[2];
const fileAbsoluteDirectory = path.dirname(path.resolve(fileName));
let buffer = '';

if (path.extname(fileName) !== '.svg') {
  console.log('\x1b[33m%s\x1b[0m', '!!!You need to supply an svg file!!!'); 
  return;
}

const createAbsolutePath = (filename) => {
  return path.resolve(fileAbsoluteDirectory, filename);
};

const getNewFilename = (current) => {
  current = current.split('.');
  current[0] = current[0] + '_CONVERTED';
  return current.join('.');
};

const randomLetter = () => {
  return String.fromCharCode(97+Math.floor(Math.random() * 26))
}

const stream = fs.createReadStream(fileName, {encoding: 'utf8'});
stream.on('data', data => {
  if (data) {
    buffer += data;
  }
});

stream.on('end', () => {
  const convertedSvg = randomizeId(buffer);
  createNewSvgFile(convertedSvg);
});

const randomizeId = (svgContents) => {
  let result;
  const ids = [];

  while (result = findIdsRegex.exec(svgContents)) {
    let replacementId = crypto.randomBytes(20).toString('hex');
    // Place random letter at front because you can't start
    // an id with a number
    replacementId = randomLetter() + replacementId;
    
    ids.push({
      id: result[1],
      replacementId: replacementId
    });
  }

  ids.forEach(idObj => {
    const idRegex = new RegExp(`id=\"(${idObj.id})\"`, "g");
    const r = new RegExp(`xlink:href=\"#(${idObj.id})\"`, "g");
    const a = new RegExp(`url\\(#${idObj.id}\\)`, "g");

    svgContents = svgContents.replace(idRegex, function(match) {
      return `id="${idObj.replacementId}"`;
    });

    svgContents = svgContents.replace(r, function(match) {
      return `xlink:href="#${idObj.replacementId}"`;
    });

    svgContents = svgContents.replace(a, function(match) {
      return `url(#${idObj.replacementId})`;
    });
  });

  return svgContents;
};

const createNewSvgFile = (svgString) => {
  const newFilename = createAbsolutePath(getNewFilename(fileName));
  fs.writeFile(newFilename, svgString, 'utf8', (err) => {
    if (!err) {
      console.log('DONE');
    }
  });
};