Saved from https://stackoverflow.com/questions/36585080/how-to-add-schema-method-in-mongoose

changemethod

var mySchema = new Schema({
      name: {
      type: String
},
   createdAt: {
   type: Date, 
   default: Date.now
}
});

mySchema.methods.changedName = function() {
    return this.name + 'TROLOLO';
};

Something = mongoose.model('Something', mySchema);