function searchFiles() {
  var results = [];
  var types = [MimeType.GOOGLE_SHEETS, MimeType.GOOGLE_DOCS];
  for (var t in types) {
    var files = DriveApp.getFilesByType(types[t]);
    while (files.hasNext()) {
      var file = files.next();
      results.push(file);
      Logger.log([file.getDateCreated(), file.getName(), file.getUrl()].join());
    }
  }
}