docs/lib/is-archived-version.js

const patterns = require('../lib/patterns')
const { deprecated } = require('../lib/enterprise-server-releases')

module.exports = function isArchivedVersion (req) {
  // if this is an assets path, use the referrer
  // if this is a docs path, use the req.path
  const pathToCheck = patterns.assetPaths.test(req.path)
    ? req.get('referrer')
    : req.path

  // ignore paths that don't have an enterprise version number
  if (!(patterns.getEnterpriseVersionNumber.test(pathToCheck) || patterns.getEnterpriseServerNumber.test(pathToCheck))) {
    return {}
  }

  // extract enterprise version from path, e.g. 2.16
  const requestedVersion = pathToCheck.includes('enterprise-server@')
    ? pathToCheck.match(patterns.getEnterpriseServerNumber)[1]
    : pathToCheck.match(patterns.getEnterpriseVersionNumber)[1]

  // bail if the request version is not deprecated
  if (!deprecated.includes(requestedVersion)) {
    return {}
  }

  return { isArchived: true, requestedVersion }
}