Functional composition for Vehicle and Motorcycle

functional_composition_example

// Define methods first. They can be used when building any object.

const readyToGo = () => {
    return {
        readyToGo() { console.log('Ready to go!') }
    }
}

const wheelie = () => {
    return {
        wheelie() { console.log('On one wheel now!') }
    }
}

// Returns a vehicle object that uses the readyToGo method
const createVehicle = () => {
    return {
        wheels: 4,
        motorized: true,
        ...readyToGo()
    }
}

// Needs a vehicle object (compare to ES6 extends with super())
// Overwrites the wheels property
// Returns a motorcycle object that has both readyToGo and wheelie methods 
const createMotorcycle = (vehicleObj) => {
    const motorcycle = { ...vehicleObj };
    motorcycle.wheels = 2;

    return {
        ...motorcycle,
        ...wheelie()
    }
}

// Create a car for Dave
const davesCar = createVehicle();
console.log(davesCar);
console.log(davesCar.wheels);
davesCar.readyToGo();

// Create a motorcycle for Dave
const davesBike = createMotorcycle(davesCar);
console.log(davesBike);
console.log(davesBike.wheels);
davesBike.readyToGo();
davesBike.wheelie();

Excellent. Thank you