title: TypeError: Cannot set property 'id' of undefined in express session(Storing session in redis)
body: <p>Iam developing Angular4 login app. I want to store session in Redis. iam using Express session. </p>
  
  <p>But I am getting the below error:</p>
  
  <pre><code> req.session.id = userName;
                                                 ^
  
  TypeError: Cannot set property 'id' of undefined
  </code></pre>