gmailAutoarchive.js

function gmailAutoarchive() {
  var labels = GmailApp.getUserLabels();
  var pattern = new RegExp("^autoarchive(\\d+)d");
  for (var a = 0; a < labels.length; a++) {
    var label = labels[a].getName()
    match = pattern.exec(label)
    if (!match || !(match[1])) {
      Logger.log("Ignoring label " + label);
      continue
    }

    var days = match[1]
    Logger.log("Processing label ("+ days + "days) " + label);
    var threads = GmailApp.search("in:inbox label:"+ label +" older_than:" + days + "d");
    
    Logger.log("found " + threads.length + " thread(s)");
//    for(var i = 0; i < threads.length; i++) {
//      var thread = threads[i];
//      Logger.log((i+1) + ". " + thread.getFirstMessageSubject());
//    }
    
    var batch_size = 100;
    while (threads.length) {
      var this_batch_size = Math.min(threads.length, batch_size);
      var this_batch = threads.splice(0, this_batch_size);
      
      GmailApp.moveThreadsToArchive(this_batch);
    }
  }
}