Nuke all Closed and Merged branches on a github web page.

nuke-branch.js

// Paste into console
// Need to disable Content Security Policy in your browser

var jq = document.createElement('script');
jq.src = "https://ajax.googleapis.com/ajax/libs/jquery/2.1.4/jquery.min.js";
document.getElementsByTagName('head')[0].appendChild(jq);

var branch_actions = $('.branch-actions');
$.each(branch_actions, function() {
  var first_child = this.children[0];
  if (first_child != undefined && $(first_child).attr('class') == 'pr-details') {
    var state = $(first_child.children[1]);
    var klass = state.attr('class');
    if (klass == "state state-closed" || klass == "state state-merged") {
      console.log($(first_child.children[1]).attr('title'))
      var form = this.children[1];
      var button = form.children[1];
      $(button).click();
    }
  }
})