Batch download Google Groups attachments

A previous known tool to batch download Google Groups messages, https://github.com/icy/google-group-crawler, does not work with the current (as of March 2023) Google Groups website.

What I needed was to download all attachments from a small number of conversations. So I used some JavaScript to automate downloading them from my browser. It works like this:

Open the Google Groups app and insert the initialization code into the Console:

function sleep(ms) {
  return new Promise(r => setTimeout(r, ms))
}

class Crawler {
  constructor() { this.links = new Set() }
  harvest() {
    Array.from(document.querySelectorAll('[aria-label=Download] a'))
      .map((a) => a.href)
      .forEach(i => this.links.add(i))
  }
  async openAll(interval) {
    this.stop = false
    for (const url of this.links) {
      window.open(url)
      await sleep(interval)
    }
  }
}

crawler = new Crawler()

For each conversation that you are interested in: open the conversation, scroll all the way down to ensure all messages have been loaded, and run crawler.harvest() in the Console.
Configure automatic download in your browser: set the appropriate download folder and enable the "save without asking" feature.
Run crawler.openAll(2000) to start opening all links. 2000 is the interval between links (in milliseconds) and you can adjust it as you like.

edudobay/google_groups_batch_download.md