Node Test js file

Car.js

function Car(config) {
    this.name = config.name;
    this.engineSize = config.engineSize;
}
Car.prototype.getEngineSize = function() {
    return this.engineSize;
};

module.exports = Car;

CarTest.js

var should = require('should');
var car = require("./car.js");
var assert = require("assert")

var mycar = new car({
    name : "Vitz",
    engineSize : 1000
});

describe('#Car()', function() {
    it('Car enginesize method test', function() {
        mycar.getEngineSize().should.equal(1000);

    })
})
describe('#Car()', function() {
    it('Car name test', function() {
        mycar.name.should.equal('Vitz');

    })
})