title: Unable to do a proper check before assigning a variable
body: <p>I have the following code</p>
  <pre><code>let sess = session
  
  let vigilances = sess.usuario.empresasVigi || 0;
  let idSess = sess.sesionUsuarioSessionStorage.sesionExt || null;
  let balance = sess.saldosUsuarioSessionStorage.saldo || 0;
  </code></pre>
  <p>Sess is an object, but sometimes it is empty so some properties will be missing
  If that happens I want the variable to be assigned the value after <code>||</code>, so I have written the code above</p>
  <p>But so far , im receiving</p>
  <pre><code>Cannot read property 'empresasVigi' of undefined
  </code></pre>