index.js

const glob = require('glob')
const Jimp = require('jimp')
const fs = require('fs')
const dir = './assets/gallery'
const thumbdir = './assets/thumbs'
const imagewidth = 1800

// export default Vanta;
// if (typeof window !== 'undefined' && window.Vue) {
//     window.Vue.component('mc-vanta', Vanta);
// }

if (fs.existsSync(dir)) {
    fs.rmdirSync(dir, { recursive: true });
}
if (fs.existsSync(thumbdir)) {
    fs.rmdirSync(thumbdir, { recursive: true });
}

if (!fs.existsSync(dir)) {
    fs.mkdirSync(dir);
}
if (!fs.existsSync(thumbdir)) {
    fs.mkdirSync(thumbdir);
}

const opt = {
    nocase: true
}
glob("assets/images/*.+(png|jpg|jpeg|svg)", opt, async function (err, images) {
    //console.log(images)

    const galleryImages = []

    for (const file of images) {
        //files.forEach(async function(file) {

        let filenameold = file.replace('assets/images/', '')
        let filename = filenameold.toLowerCase().replace(/[^\w.]+/g, "_")

        //galleryImages.push('assets/gallery/' + filename)

        Jimp.read(file)
            .then(jfile => {
                if (jfile.bitmap.width > imagewidth) {
                    console.log('resizing ' + filename)
                    return jfile
                        .resize(imagewidth, Jimp.AUTO) // resize
                        .quality(60) // set JPEG quality
                        .write(dir + '/' + filename); // save
                } else {
                    fs.copyFile(file, dir + '/' + filename, (err) => {
                        if (err) throw err;
                        console.log(filename + ' copied to gallery (smaller than ' + imagewidth + ')');
                    });
                }
            })
            .catch(err => {
                console.error(err);
            });

        // Create thumbnails
        Jimp.read(file)
            .then(jfile => {
                width = 120
                height = Jimp.AUTO
                if (jfile.bitmap.height < jfile.bitmap.width) {
                    width = Jimp.AUTO
                    height = 120
                }
                return jfile
                    .resize(width, height, Jimp.RESIZE_BEZIER) // resize
                    .quality(60) // set JPEG quality
                    .write(thumbdir + '/' + filename); // save
            })
            .catch(err => {
                console.error(err);
            });

    }

})