const BlacklistAPI = require('../BlacklistAPI'); function checkBlacklist(req, res, next) { BlacklistAPI.includesPackage(req.packageName).then( blacklisted => { // Disallow packages that have been blacklisted. if (blacklisted) { res .status(403) .type('text') .send(`Package "${req.packageName}" is blacklisted`); } else { next(); } }, error => { console.error('Unable to fetch the blacklist: %s', error); // Continue anyway. next(); } ); } module.exports = checkBlacklist;