Downsize retina assets (Node.js) script

downsize-assets.js

#!/usr/bin/env node

/* eslint-disable @typescript-eslint/no-var-requires */

const { join, basename, dirname } = require('path');

const Jimp = require('jimp');
const glob = require('fast-glob');
const color = require('cli-color');

const BASE_DIRS = ['public'];
const EXTENSIONS = ['png', 'jpeg', 'jpg', 'gif'];
const TARGET_SUFFIX = '@2x';
const SCALE_AMOUNT = 0.5;

/**
 * Downsize retina assets script
 *
 * Recursively look for all retina assets (suffixed with @2x) and generate
 * scaled down versions
 */

const downsize = async filename => {
  console.log(color.blue(`Downsizing ${color.cyan(filename)}…`));

  const outPath = join(
    dirname(filename),
    basename(filename).replaceAll(TARGET_SUFFIX, '')
  );

  const image = await Jimp.read(filename);

  image.scale(SCALE_AMOUNT);

  await image.writeAsync(outPath);

  console.log(`${color.green('✓')} Saved resized to ${outPath}`);
};

const run = async () => {
  const files = await glob(
    `./(${BASE_DIRS.join('|')})/**/*${TARGET_SUFFIX}.(${EXTENSIONS.join('|')})`
  );

  await Promise.all(files.map(downsize));
};

run();