A simple Node.js script to generates assets for srcSet from a base asset using sharp.

generate-srcSet.js

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

// Set your sizes array based on the needs of your application.
const sizes = [
  { width: 480, suffix: 'sm' },
  { width: 800, suffix: 'md' },
  { width: 1080, suffix: 'lg' },
  { width: 1280, suffix: 'xl' },
  { width: 1600, suffix: 'xxl' }
];

function generateSrcSet(dir) {
  fs.readdirSync(dir).forEach((file) => {
    const basename = path.basename(file);
    const ext = path.extname(file);
    const filePath = `${dir}/${file}`;
    
    Promise.all(
      sizes.map(({ width, suffix }) => (
        sharp(filePath).resize(width).toFile(`${dir}/${basename}-${suffix}.${ext}`)
      ))
    ).then(() => {
      console.log('Image resize succeeded!');
    }).catch((err) => {
      console.error(`Image resize failed with error: ${err}`);
    });
  });
}