optimizeSVGs.js

// samayo/country-json/country-by-flag.json

// node

const fs = require('fs');
const {optimize} = require('svgo');

// const filename = '2-countries-by-flag.json';
const filename = 'country-by-flag.json';

console.log(`Start processing SVGs within the file ${filename}`);

let optimizedSVGs = [];

fs.readFile(filename, 'utf8', (err, data) => {
  if (err) {
    console.error(`Error reading file: ${err}`);
    return;
  }

  const json = JSON.parse(data);
  console.log(`Processing ${json.length} countries`);

  json.forEach((jsonElement) => {
    let {country, flag_base64} = jsonElement;

    if (!flag_base64) {
      console.warn(`No flag for ${country}!`);
      return;
    }

    let svgString = Buffer.from(
      flag_base64.replace(/^data:image\/svg\+xml;base64,/, ''),
      'base64'
    ).toString('utf8');

    const filename = `flags/${country}.svg`;

    const result = optimize(svgString, {
      path: filename,
      multipass: true, // all other config fields are available here
    });

    const buffer = Buffer.from(result.data, 'utf8');

    fs.writeFile(filename, buffer, (err) => {
      if (err) {
        console.error(`Error writing file: ${err}`);
        return;
      }
    //   console.log(`File written: ${filename}`);
    });

    console.log(`Optimized flag for ${country}.`);

    optimizedSVGs.push({
      ...jsonElement,
      flag_base64: `data:image/svg+xml;base64,${Buffer.from(result.data, 'utf8').toString('base64')}`,
    });
  });

  const newFilename = filename.replace('.json', '') + '-optimized.json';
  fs.writeFile(newFilename, JSON.stringify(optimizedSVGs, null, ''), (err) => {
    if (err) {
      console.error(`Error creating file: ${err}`);
      return;
    }
    console.log(`File created: ${newFilename}`);
  });

});