title: Mongoose - save document Object.assign
body: <p>I have a mongoose document, and i want to update many fields on it with another object. something like</p>
  
  <pre><code>Model.findById(_id, function (err, doc){
      var updateData = {...data}
  
      // i do not want to do 
      doc.foo = data.foo;
      doc.bar = data.bar;
  
      // i need something like
      doc.save(updateData)
      // or
      doc.update(updateData)
      // or
      doc = {...doc, ...updateData}
      doc.save();
  
  });
  </code></pre>
  
  <p>the updateData is a object with all the data i need to update in the doc.</p>
  
  <p>didn't found any doc related, the closest was a find one and update...</p>