Neulabs Backend Assessment

Requirements

Docker must be installed in the machine to be able to run the compose file.

Constraints

Feel free to add any services to the compose if you feel like doing it or use any framework you want! The only constraint for this test is that solution of the assessment must be written in TypeScript.

Setup

From the root folder of the project

docker-compose up -d
npm run migrate

Implementation Context

This assessment is a real (but simplified) operational flow that we have already implemented.

The purpose of this flow is to process realtime incoming order events purchased by customers.
For each order that enters the system, it must understand if the order is shippable and, when it is, with
which courier.

Any of the architectural and project structure choices are up to you.

Assessment

Given the input structured as the example bellow, develop a solution that will elaborate the order with the
following specs:

1. if the order contains more than 3 unique items (ignore the quantity of each item) the order must be split in
   n sub-orders (called fulfillments from now on. Look at the example to see how a fulfillment is structured).

2. each generated fulfillment must contain a detail of all the products adding the weight and price that can be found on the database. (assume that the weight is in grams and the price is in euro)

   You need to update the quantity of each product in the database when making these fulfillments.

3. for each generated fulfillment we need to select the courier by applying the following rules:

• if there are 1 or 2 unique items, still excluding the quantity, in the fulfillment then we pick a random courier from the available courier in the database
• if it contains 3 items then we take the sum of the weight (this time we take quantity into account) of all the products,
  and we select the courier with the lower cost (based on the courier_price_range table) using the total
  calculated weight

Extra:

1. store the orders and the fulfilments
2. handle the case if a product is not shippable with any courier, store the order with an error state (for example the weight is too high and there's no way to ship it or there's no more quantities in the database)

Additional Notes

• The user must not be saved for privacy issue.
• The ranges of the weight table must be considered start inclusive and end exlcusive, so: [start, end)

Example

Given the following input:

{  
    "id": "OrderId1",  
    "customer": {  
        "id": "1",  
        "email": "[email protected]",  
        "firstName": "Nome",  
        "addresses": [  
            {  
                "city": "City",  
                "apartmentNumber": 27,  
                "street": "Via Di casa",  
                "fullName": "Nome Cognome"  
            }  
        ],  
        "phoneNumber": "+39 333 008 3333",  
        "lastName": "Cognome"  
    },  
    "addressInfo": {  
        "city": "City",  
        "name": "Nome Cognome",  
        "apartmentNumber": 27,  
        "street": "Via Di casa",  
        "fullName": "Nome Cognome"  
    },  
    "lineItems": [  
        {  
            "id": "id1",  
            "name": "Prod1",  
            "qta": 5  
        },  
        {  
            "id": "id2",  
            "name": "Prod2",  
            "qta": 1  
        },  
        {  
            "id": "id3",  
            "name": "Prod3",  
            "qta": 3  
        },  
        {  
            "id": "id4",  
            "name": "Prod4",  
            "qta": 3  
        }  
    ]  
}  

The expected output is the generation of 2 fulfillments like the following:

{
  "id": "1",
  "orderId": "OrderId1",
  "customer": {
    "id": "1",
    "email": "[email protected]",
    "firstName": "Nome",
    "addresses": [
      {
        "city": "City1",
        "apartmentNumber": 27,
        "street": "Via Di casa",
        "fullName": "Nome Cognome"
      }
    ],
    "phoneNumber": "+39 333 008 3333",
    "lastName": "Cognome"
  },
  "shippingAddress": {
    "city": "City1",
    "apartmentNumber": 27,
    "street": "Via Di casa",
    "fullName": "Nome Cognome"
  },
  "products": [
    {
      "id": "id1",
      "name": "Prod1",
      "qta": 5,
      "weight": 10,
      "price": 10
    },
    {
      "id": "id2",
      "name": "Prod2",
      "qta": 1,
      "weight": 11,
      "price": 20
    },
    {
      "id": "id3",
      "name": "Prod3",
      "qta": 3,
      "weight": 12,
      "price": 30
    }
  ],
  "courier": "PDB"
}  

{  
    "id": "1",  
    "orderId": "OrderId1",  
    "customer": {  
        "id": "1",  
        "email": "[email protected]",  
        "firstName": "Nome",  
        "addresses": [  
            {  
                "city": "City1",  
                "apartmentNumber": 27,  
                "street": "Via Di casa",  
                "fullName": "Nome Cognome"  
            }  
        ],  
        "phoneNumber": "+39 333 008 3333",  
        "lastName": "Cognome"  
    },  
    "shippingAddress": {  
        "city": "City",  
        "apartmentNumber": 27,  
        "street": "Via Di casa",  
        "fullName": "Nome Cognome"  
    },  
    "products": [  
        {  
        "id": "id4",  
        "name": "Prod4",  
        "qta": 3,  
        "weight": 15,  
        "price": 21  
        }  
    ],  
    "courier": "BRT"  
}