Google App Script for listing all image files in directory and getting links to them

FileLister.gs

function listAllFiles() {
  var sheets = SpreadsheetApp.getActiveSpreadsheet();
  var sheet = sheets.getActiveSheet();
  var cell = sheet.getActiveCell();
  var to_visit = [DriveApp.getFolderById("<id>")];
  var info = [], f;
  var q = '"';
  while (to_visit.length > 0) {
    var cur_folder = to_visit.pop();
    var files = cur_folder.getFiles();
    while (files.hasNext()) {
      f = files.next();

      if (!(f.getName().endsWith(".jpg") || f.getName().endsWith(".png"))) {
        continue;
      }

      var parent = f.getParents().next();
      var path = f.getName();
      while (true) {
        path = parent.getName() + "/" + path;

        if (parent.getParents().hasNext()) {
          parent = parent.getParents().next();
        } else {
          break;
        }
      }
      
      var valid_url = q + f.getUrl() + q;
      var valid_path = q + path + q;
      info.push([valid_url, valid_path]);
    }

    var subfolders = cur_folder.getFolders();
    while (subfolders.hasNext()) {
      f = subfolders.next();
      to_visit.push(f);
    }
  }
  sheet.getRange(cell.getRow(), cell.getColumn(), info.length, 2).setValues(info);
}