Express.js Download Streamed Zip

index.ts

import express from 'express';
import archiver from 'archiver';

express().use('/download-assets', async (req, res) => {
    res.set('Content-Type', 'application/octet-stream');
    res.set('Transfer-Encoding', 'chunked');
    res.attachment(`assets.zip`);

    console.log(`Archiving project assets...`);
    const zipfile = archiver('zip');
    zipfile.on('error', (err: any) => {
        console.log(`zip error: ${err}`);
        res.status(500).json({ msg: `download assets failed: ${err}` });
    });
    zipfile.on('end', () => {
        console.log('Done');
        res.status(200).end();
    });
    zipfile.on('entry', (e: { name: any }) => {
        process.stdout.write(`\rarchiving ${e.name}${' '.repeat(5)}`);
    });

    zipfile.pipe(res, { end: true });
    zipfile.directory(this.projectRoot, false);
    zipfile.finalize();
})