invite-all-slack-members-to-a-channel.js

function sleep(ms) {
  return new Promise(resolve => setTimeout(resolve, ms));
}
var letters = ["a","b","c","d","e","f","g","h","i","j","v","k","l","m","n","o","p","q","r","s","t","u","v","z"];
async function inviteAllUsers() {      
   for(var i = 0; i < letters.length; i++){
      await sleep(300);
    $('#channel_actions_toggle').click();
      await sleep(300);
    $('#channel_invite_item').click();
      await sleep(300);
     for(var k = 0; k < letters.length; k++){
        var word = letters[i] + letters[k];
        await sleep(300);
        $("#channel_invite_filter").val(word).trigger("input");
        $(".channel_invite_member:not(hidden)").each(function(i, obj) {
            foundAny=true;
            this.click();
        });
      }
      await sleep(300);
      $('.invite_go').click()
    }
}

inviteAllUsers(); 
setInterval(inviteAllUsers,600*1000);