gillchristian/didactic-goggles

:package: A simple cart API

Cart API

Run

To run the app in production mode in the Docker 🐳 container.

cat sample.env > .env
docker-compose up -d

To run the app in production mode in the local machine.

cat sample.env > .env
yarn
yarn build
yarn start

API documentation

Data API (dummy endpoints)

These are the available endpoints of the cart:

• List items (available items in store)

GET /items

type Price = Int -- cents
type SKU = String

data Item = Item
  { sku         :: SKU -- i.e. ID
  , price       :: Price
  , displayName :: String
  } deriving (Eq, Show)


data ItemsResponse = ItemsResponse
  { data  :: [Item]
  , count :: Int
  } deriving (Eq, Show)

• List discounts (available discounts)

GET /discounts

type Percentage = Int -- 10, 20, 30, ..., 100
type DiscountCode = String

data Discount = Discount
  { code          :: DiscountCode
  , percentage    :: Percentage
  } deriving (Eq, Show)


data DiscountsResponse = DiscountsResponse
  { data  :: [Discount]
  , count :: Int
  } deriving (Eq, Show)

Cart API

• Show cart

GET /user/:user_id/cart

data Cart = Cart
  { totalPrice :: Price
  , items      :: Map SKU Amount -- { [sku]: amount }
  , discount   :: Maybe DiscountCode
  } deriving (Eq, Show)


data CartResponse = CartResponse
  { data :: Cart
  } deriving (Eq, Show)

• Mutate cart (add/remove item, increase/decrease count, apply discount code, empty cart)

PUT /user/:user_id/cart

type Count = Int

data Mutation
  = AddItem SKU Count
  | UpdateItem SKU Count
  | DeleteItem SKU
  | ApplyDiscountCode DiscountCode
  | EmptyCart
  deriving (Show, Eq)


data RequestBody = RequestBody
  { mutation :: Mutation
  } deriving (Eq, Show)


data MutationResponse = MutationResponse
  { data :: Cart
  } deriving (Eq, Show)

NOTE: fixtures.txt has predefined mutations to send for testing (using the dummy data of /items & /discounts).

Events API

These are the events tracked when mutating the user's carts.

type UserID = String

data Event = Event
  { time     :: Time
  , userID   :: UserID
  , mutation :: Mutation
  } deriving (Eq, Show)

• List events (all the history of events)

GET /events

data EventsResponse = EventsResponse
  { data  :: [Event]
  , count :: Int
  } deriving (Eq, Show)

• List events for a user

GET /events/:user_id

data EventsResponse = EventsResponse
  { data :: [Event]
  , count :: Int
  } deriving (Eq, Show)