This repository contains a Go programming exercise for interview candidates. You'll be developing an API for an online shopping cart in the Go programming language.

This is a REST API for basic CRUD operations for an online shopping cart. Data should be persisted in a storage layer which can use Postgres.

You should use default net/http package for REST implementation; sqlx or sqlc for interact with postgres; all the queries should be wrote mannually (no ORM, no Select methods and etc.); your repo should be private.

Cover your code with the unit tests (you could use testify).

Create a Dockerfile for your application.

The Cart API consists of two simple types: Cart and CartItem. The Cart holds zero or more CartItem objects.

CartItem objects should be created in DB exactly (not from application).

A new cart should be created and an ID generated. The new empty cart should be returned.

POST http://localhost:3000/carts -d '{}'

{
	"id": 1,
	"items": []
}

A new item should added to an existing cart. Should fail if the cart does not exist, if the product name is blank, or if the quantity is non-positive. The new item should be returned.

POST http://localhost:3000/carts/1/items -d '{
	"product": "Shoes",
	"quantity": 10
}'

{
	"id": 1,
	"cart_id": 1,
	"product": "Shoes",
	"quantity": 10
}

An existing item should be removed from a cart. Should fail if the cart does not exist or if the item does not exist.

DELETE http://localhost:3000/carts/1/items/1

{}

An existing cart should be able to be viewed with its items. Should fail if the cart does not exist.

GET http://localhost:3000/carts/1

{
	"id": 1,
	"items": [
		{
			"id": 1,
			"cart_id": 1,
			"product": "Shoes",
			"quantity": 10
		},
		{
			"id": 2,
			"cart_id": 1,
			"product": "Socks",
			"quantity": 5
		}
	]
}