compress.js

const brotli = require('brotli');
const fs = require('fs');
const zlib = require('zlib');

const brotliSettings = {
    extension: 'br',
    skipLarger: true,
    mode: 1,
    quality: 10,
    lgwin: 12
}

let dirs = ['src', 'public']
dirs.forEach(dir => {
    fs.readdirSync(dir).forEach(file => {
        if (file.endsWith('.js') || file.endsWith('.css') || file.endsWith('html')) {
            // brotli
            const result = brotli.compress(fs.readFileSync(dir + '/' +  file), brotliSettings);
            fs.writeFileSync(dir + '/' + file + '.br', result);
            //  gzip
            const fileContents = fs.createReadStream(dir + '/' + file);
            const writeStream = fs.createWriteStream(dir + '/' + file + '.gz');
            const zip = zlib.createGzip();
            fileContents
                .pipe(zip)
                .on('error', err => console.error(err))
                .pipe(writeStream)
                .on('error', err => console.error(err))
        }
    })
})