Go decorator pattern

sample.go

// You can edit this code!
// Click here and start typing.
package main

import "fmt"

type IFeature interface {
	GetPrice() int
}

type BasicMaintenance struct{}

func (BasicMaintenance) GetPrice() int {
	featureCost := 5

	return featureCost
}

type EmailFeature struct {
	BaseFeature IFeature
}

func (e *EmailFeature) GetPrice() int {
	featureCost := 10

	if e.BaseFeature != nil {
		return e.BaseFeature.GetPrice() + featureCost
	}

	return featureCost
}

type ChatFeature struct {
	BaseFeature IFeature
}

func (c *ChatFeature) GetPrice() int {
	featureCost := 5

	if c.BaseFeature != nil {
		return c.BaseFeature.GetPrice() + featureCost
	}

	return featureCost
}

type CalendarFeature struct {
	BaseFeature IFeature
}

func (c *CalendarFeature) GetPrice() int {
	featureCost := 15

	if c.BaseFeature != nil {
		return c.BaseFeature.GetPrice() + featureCost
	}

	return featureCost
}

func main() {
	f := CalendarFeature{
		BaseFeature: &EmailFeature{
			BaseFeature: &BasicMaintenance{},
		},
	}
	fmt.Println("Total price:", f.GetPrice())
}