header-auth-middleware.js

const apiKeyToUser = {
  '76b1e728-1c14-43f9-aa06-6de5cbc064c2': 'hugo',
};

const apiKeys = new Set(Object.keys(apiKeyToUser))

const isApiKey = key => apiKeys.has(key)

function headerAuth(req, res, next) {
  if (req.session.data) {
    return next()
  }

  const authenticationHeader = req.get('authorization')

  if(!authenticationHeader) {
    return next()
  }

  const apiKey = authenticationHeader
    .replace('Bearer', '')
    .trim();

  if (!isApiKey(apiKey)) {
    return next()
  }

  req.session.data = { username: apiKeyToUser[apiKey] };

  next();
}

module.exports = headerAuth;