This is my submission for the Shopify Summer 2019 Backend Developer Intern Challenge.
https://damian-reiter-shopify-dev.herokuapp.com
I created the barebones online marketplace using Ruby on Rails. It supports all the basic functionality requested, as well as a session-based shopping cart, discount codes, and item filtering by category.
The database is re-seeded every hour (at :00) in order to reset the stock of items in case you want to keep testing more :)
❗ All endpoints are configured to use HTTP GET. In a real-world scenario, I wouldn't use GET for everything, and I know this doesn't follow best practices. I opted for ease-of-demoability, so all functionality can be explored via a web browser without needing external tools such as Postman ❗
| Endpoint | Description | Parameters (if any) | Example |
|---|---|---|---|
| /items | list all items | available [Boolean]: if true, only show items in stock category [String]: only show items with a specific category |
GET /items?available=true&category=toys |
| /items/:id | list item with specific id | N/A | GET /items/1 |
| /items/:id/purchase | purchase specific item (cart independent) | N/A | GET /items/1/purchase |
| /cart | show cart metadata and contents | N/A | GET /cart |
| /cart/add/:id | add item with specific id to cart | N/A | GET /cart/add/2 |
| /cart/checkout | purchase all items currently in cart | N/A | GET /cart/checkout |
| /cart/discount/:code | add a discount code to cart. | N/A | GET /cart/discount/25off |
The Item model represents each item for sale.
Schema:
- title: String
- price: Float
- inventory_count: Integer
- category: String
The CartItem model is simply a reference to a specific Item and Cart.
A single Item can have many CartItems. For example:
Item 1
|
------------------------------------
| | |
CartItem 1 CartItem 2 CartItem 3
|-- cart_id: 1 |-- cart_id: 4 |-- cart_id: 7
|-- item_id: 1 |-- item_id: 1 |-- item_id: 1
|-- quantity: 2 |-- quantity: 1 |-- quantity: 5
This shows that carts 1, 4, and 7 each contain varying quantities of Item 1.
Schema:
- item_id: Integer
- cart_id: Integer
- quantity: Integer, default => 1
The Cart model is used as a collection of CartItems.
Each Cart is tied to a user session. On each new session, a new Cart will be implicitly created when you access a /cart route and will be associated with your current session. Every time you re-visit /cart, the controller will display the contents of your active Cart tied to your session.
CartItems are added to your Cart by visiting /cart/add/:id, where id is the id of the Item you wish to add. If your active Cart already contains a CartItem with item_id equal to id, it will increase the quantity of that CartItem by 1. If not, it will add a new CartItem to the Cart.
You can checkout your Cart by visiting /cart/checkout. When you checkout, each CartItem in your Cart is iterated over. Each CartItem has its corresponding Item's inventory_count updated to reflect the quantity purchased. Cart#check_inventory ensures that a CartItem's quantity cannot be greater than the corresponding Item's inventory_count due to multiple active Carts containing the same items.
Schema:
- subtotal: Float
- total: Float
- discount: Float
- discount_code: String
❗ note: I just threw this part in for fun, don't feel as though you have to play along, I won't mind :)
I added one discount code which can be applied to your cart by accessing /cart/discount/:code.
I recently learned about CTFs and was inspired to make a mini-challenge to reveal the discount code =).
The discount code is hidden somewhere in my project (a good place to start looking is in the /config directory).
If you don't want to see if you can find it and just want to test out my discount code functionality, click here to reveal the code ->
reveal code
code is: charaAs this feature was a bit of an afterthought, I just stored the discount code in an environment variable. In a real application, I would make a rails Discount model with the following schema:
- code: String
- active: Boolean
- start_date: Integer (seconds since epoch)
- end_date: Integer (seconds since epoch)
- fixed_amount: Float
- percentage_amount: Integer
- min_cart_items: Integer (min items required in cart for this code to be applied)
- min_cart_subtotal: Float (min cart subtotal required for this code to be applied)
- category: String (only apply discount to items with this category)