Google Apps Script that adds GitHub repo and PR labels to your Gmail inbox

Code.gs

function processInbox() {
  var threads = GmailApp.search("is:unread in:inbox has:nouserlabels from:notifications@github.com newer_than:1h");
  
  for (var i = 0; i < threads.length; i++) {
    var messages = threads[i].getMessages();

    for (var j = 0; j < messages.length; j++) {
       processMessage(messages[j]);
    }
  }
}

function processMessage(message) {
  var body = message.getRawContent();
  var subject = message.getSubject();
  var subjectFilter = "[EddyVerbruggen/"; // you may want to adjust this line, to filter only your own repos

  if (subject.indexOf(subjectFilter) > -1) {
    var repo = subject.substring(subject.indexOf("/") + 1, subject.indexOf("]"));
    
    if (repo) {
      // add the 'my-github-repo' label
      if (!GmailApp.getUserLabelByName(repo)) {
        GmailApp.createLabel(repo);
      }
      message.getThread().addLabel(GmailApp.getUserLabelByName(repo));
      
      // add the 'PR' label, if applicable
      var isPullRequest = body.indexOf("/pull/") > -1;
      if (isPullRequest) {
        if (!GmailApp.getUserLabelByName("PR")) {
          GmailApp.createLabel("PR");
        }
        message.getThread().addLabel(GmailApp.getUserLabelByName("PR"));
      }
    }   
  }
}