Search mails by labels in Inbox - mail.google.com

search_mails_by_labels_in_inbox.user.js

// ==UserScript==
// @name        Search mails by labels in Inbox - mail.google.com
// @namespace   https://msyk.hgsn.info/
// @match       https://mail.google.com/mail/u/*
// @grant       GM_registerMenuCommand
// @grant       GM_getValue
// @version     1.0
// @author      Masayuki Higashino
// ==/UserScript==

function label_names_to_search_uri(label_names) {
  let base_uri = document.location.href.split('/').slice(0, 6).join('/');
  let search_query = '((label:inbox) AND (' + label_names.map(label_name => 'label:' + label_name).join(' OR ') + '))';
  let target_uri = base_uri + '/#search/' + encodeURIComponent(search_query);
  return target_uri;
}

function search_mails_by_labels_in_inbox() {
  let labels = GM_getValue('labels', []);
  let uri = label_names_to_search_uri(labels);
  document.location.href = uri;
}

GM_registerMenuCommand("Search mails by labels in Inbox", search_mails_by_labels_in_inbox);