checkout-challenge

README

Project Overview

This is a small project to simulate in simple way the way we add items and checkout from cart.

Limitation

• Doesn't support custom data loading (we can add it later on)
• Currency formatting is tied to $

Project Structure

This project consists two main packages

stock package

This package is responsible for mantaining the item information details

This package has an entity which is structured like this

type StockItem struct {
	SKU          string
	Name         string
	Price        float64
	InventoryQty int64
}

Under this package we have repository & service to mantain data flow

cart package

This package is responsible for handling activities:

• Add item to cart
• Checkout

Also in this package, checkout price was calculated based on grl files

This is an example of grl file

rule MacbookRule "When you buy Macbook, you got Raspberry PI B For free" {
    when
        CartItem.SKU == "43N23P" && MappedCartItem["234234"].Qty > 0
    then
        MappedSku["234234"].Price = 0;
        Retract("MacbookRule");
}

rule GoogleSpeaker "When you buy 3 google speaker, only pay for 2" {
    when
        CartItem.SKU == "120P90" && MappedCartItem[CartItem.SKU].Qty >= 3
    then
        MappedCartItem[CartItem.SKU].Qty = MappedCartItem[CartItem.SKU].Qty - 1;
        Retract("GoogleSpeaker");
}

rule AlexSpeaker "When you buy more than 3 alexa speakers, got 10% off on each item of this speakers" {
    when
        CartItem.SKU == "A304SD" && MappedCartItem[CartItem.SKU].Qty >= 3
    then
        MappedSku[CartItem.SKU].Price = MappedSku[CartItem.SKU].Price - (MappedSku[CartItem.SKU].Price * 10 / 100);
        Retract("AlexSpeaker");
}


rule GeneralPrice "Otherwise" {
    when
        MappedCartItem[CartItem.SKU].Qty > 0
    then
        Log(MappedSku[CartItem.SKU].String());
        Checkout.TotalPrice = Checkout.TotalPrice + MappedSku[CartItem.SKU].Price * CartItem.Qty;
        MappedCartItem[CartItem.SKU].Qty = 0;
}

This .grl file will act as knowledge base to determine what price should be paid by the customer.

Unit Test

Under each of the package, i add some test cases. You can find in either of the following files or folders

• test/
• [file]_test.go

Run the project

This project doesn't support sophisticated data mantaining. It wants to as simple as it could be.

So to run this project, you should prepare a file. The file has the following structure

FIRST LINE will be ID
[SKU] 2 .. N LINE will be SKU

example

KENNY
43N23P
234234

To process it, simply run this command on your terminal

go run . -input .\in.txt

It will print the total checkout price

Total: $5399.99