RocketChat.Migrations.add({ version: 35, up() { return RocketChat.models.Messages.update({ 'file._id': { $exists: true }, 'attachments.title_link': { $exists: true }, 'attachments.title_link_download': { $exists: false } }, { $set: { 'attachments.$.title_link_download': true } }, { multi: true }); } });