title: Mongoose Model.find().select() If Select is an empty string What's returned?
body: <p>Let's assume that we're using a simple schema of this:</p>
  
  <pre><code>const phoneRegex = require('./phoneRegex');
  const Schema = require('mongoose').Schema;
  const PersonSchema = new Schema({
    firstName: String,
    lastName: String,
    phone: {
      type: String,
      regex: phoneRegex,
    },
    Address: {
      street1: String,
      street2: String,
      city: String,
      state: String,
      zip: String,
    }
  });
  
  module.exports = Person = require('mongoose').model('Person', PersonSchema);
  </code></pre>
  
  <p>and I want to have a preset call to mongoose to find a list of people, but I want to have the option to limit what's returned from the database. I understand I can use the <code>select()</code> function of the model, but what happens when you provide an empty string? (i.e. <code>Person.find(options).select('');</code>) </p>
  
  <p>My predefined function looks like this:</p>
  
  <pre><code>//sample options object.
  const options = {
    firstName: {
      $regex: '^John',
      $options: 'i',
    },
  };
  const Person = require('./person');
  const fetchAll = (Options, select = '') =&gt; {
    return Person.find(Options).select(select);
  };
  </code></pre>
  
  <p>I understand that I would want to pass the property name to select it for return, but is an empty selection string the same as "SELECT NONE"?</p>