Mongoose.js: force always populate

this plugin is a solution to your question:

https://www.npmjs.com/package/mongoose-autopopulate

With Mongoose 4.0, you can use Query Hooks in order to autopopulate whatever you want.

Below example is from introduction document by Valeri Karpov.

Definition of Schemas:

var personSchema = new mongoose.Schema({
  name: String
});

var bandSchema = new mongoose.Schema({
  name: String,
  lead: { type: mongoose.Schema.Types.ObjectId, ref: 'person' }
});

var Person = mongoose.model('person', personSchema, 'people');
var Band = mongoose.model('band', bandSchema, 'bands');

var axl = new Person({ name: 'Axl Rose' });
var gnr = new Band({ name: "Guns N' Roses", lead: axl._id });

Query Hook to autopopulate:

var autoPopulateLead = function(next) {
  this.populate('lead');
  next();
};

bandSchema.
  pre('findOne', autoPopulateLead).
  pre('find', autoPopulateLead);

var Band = mongoose.model('band', bandSchema, 'bands');