Sequelize DataTypes not being validated
<p>I've been learning Node.JS as of recently, and I'm currently using Sequelize.
I have a problem with the update method; it updates just fine, but when I input values that should be incompatible with an attribute's datatype, it still passes it, and updates it in the database.</p>

<p>For exemple: in Postman, when I try to update a record's "completed" attribute with a string, it gets updated even though the datatype was specified as a Boolean, and delivers no error message(request status is 200).
Here is the code:</p>

<ul>
<li><p>todo model:</p>

<pre><code>module.exports = function (sequelInst, DataTypes){
  return sequelInst.define('todo', {
    description: {
      type: DataTypes.STRING,
      allowNull: false,
      validate: {
        len: [1, 250]
      }
    },
    completed: {
      type: DataTypes.BOOLEAN,
      allowNull: false,
      defaultValue: false
    }
  });
};
</code></pre></li>
<li><p>server.js:</p>

<pre><code>    ...

    app.put('/todos/:id', function(req,res){
      var body =_.pick(req.body, 'description', 'completed');
      var attributes = {};
      var paramId = parseInt(req.params.id, 10);

      if( body.hasOwnProperty('completed')){
        attributes.completed = body.completed;
      }

      if( body.hasOwnProperty('description')) {
        attributes.description = body.description;
      }

      db.todo.findById(paramId)
      .then(function(todo){ // First Promise Chain
        if(todo){
          return todo.update(attributes);
        }
        else{
          res.status(404).send("No todo corresponding to id");
        }
      }, function () {
        res.status(500).send("Server Error");
      })
      .then(function(todo) { // Second Promise Chain
        res.send(todo);
      }, function (e){
        res.status(400).json(e);
      });

    });
</code></pre></li>
</ul>