Checking how to know old attribute values in mongoose middleware

app.js

var mongoose = require('mongoose'),
    moment = require('moment');

mongoose.connect('mongodb://127.0.0.1:27017/test', function(err) {
    if (err) {
        throw err;
    }

    var TestModel = require('./TestModel');

    TestModel.findOne({}, function(err, doc) {
        if (!doc) {
            var doc = new TestModel();
        }

        doc.name = 'Test 1 - ' + moment().format('HH:mm:ss:SS');
        doc.ready = !doc.ready;

        doc.save(function(err) {
            if (err) {
                throw err;
            }

            mongoose.connection.close();
        });
    });
});

package.json

{
  "name": "test-model-attribute-old-value",
  "version": "0.0.1",
  "description": "Checking how to know old attribute values in mongoose middleware",
  "main": "app.js",
  "dependencies": {
    "moment": "^2.10.3",
    "mongoose": "^4.0.7"
  },
  "devDependencies": {},
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC"
}

TestModel.js

var mongoose = require('mongoose'),
    Schema = mongoose.Schema;

var testModelSchema = new Schema({
    name: String,
    ready: {type: Boolean, default: false}
});

testModelSchema.pre('init', function(done) {
    console.log('------------------');
    console.log('Pre init attributes');

    if (!this.isNew) {
        console.log(this);
    } else {
        console.log('The doc is new, run app once again');
    }

    console.log('------------------');
    done();
});

testModelSchema.post('init', function(model) {
    console.log('------------------');
    console.log('Post init attributes');

    if (!this.isNew) {
        console.log(model);
        model.oldValues = JSON.parse(JSON.stringify(model));
        console.log('Setting this.oldValues');
    } else {
        console.log('The doc is new, run app once again');
    }
    console.log('------------------');
});

testModelSchema.pre('save', function(done) {
    console.log('------------------');
    console.log('Pre save attributes');
    if (!this.isNew) {
        console.log(this);
    } else {
        console.log('The doc is new, run app once again');
    }

    this.wasNew = this.isNew; // this is just for post('save') to knew
    console.log('------------------');
    done();
});

testModelSchema.post('save', function(model) {
    console.log('------------------');
    console.log('Post save attributes');

    if (!model.wasNew) {
        console.log(model);

        console.log('The old attributes (model.oldValues)')
        console.log(model.oldValues);
    } else {
        console.log('The doc is new, run app once again');
    }
    console.log('------------------');
});

module.exports = mongoose.model('TestModel', testModelSchema);