Download all downloadable links in a single zip archive

download-all-linked-files.js

const links = document.querySelectorAll('a[download]')

if (links.length === 0) {
    console.log("No downloadable files found")
    return
}

const handle = await showSaveFilePicker({ 
    suggestedName: 'files.zip', 
    types: [{ 
        accept: { 
            'application/zip': ['.zip'] 
        } 
    }] 
})

const writer = await handle.createWritable()

const { default: JSZip } = await import('https://esm.sh/jszip')

const zip = new JSZip()

for (const link of links) { 
    const filename = link.getAttribute('download') // TODO: Content-Disposition response header?
    if (filename) {
        const data = fetch(link.getAttribute('href')).then(response => response.arrayBuffer())
        zip.file(filename, data) 
    }
}

zip.generateInternalStream({ type: 'uint8array', streamFiles: true })
    .on('data', data => writer.write(data))
    .on('error', err => writer.error(err))
    .on('end', () => writer.close())
    .resume()