BCGChallange

Requirements

Java 11

Running

Run project using the following commands
Using default file in assessment:

mvn -q spring-boot:run 

Tests

mvn test

Structure

I used Hexagonal architecture (or ports and adapters architecture) as the architectural pattern of the project. There are four separated layers which are as below:

Presentation

This layer contains the user interface for getting input data from the client, passing it as a command or query request to the application layer, and format results for the client and pass it as a response.

Application

This is where business use cases are located. Request from the presentation layer is processed here, communicating with the core layer and calls to the infrastructure layer happen in this layer.

Core

Core business rules, logics, and invariants are in this layer. This layer is developed using the Model-Driven Design approach.

Infrastructure

Any communication with the outer world and concrete implementation of ports from higher layers locate here.

Testing

The project is developed using Test-Driven Design approach. As a result of a layered architecture without direct dependencies between layers, I was able to test each layer in full isolation. In the heart of the system, the core layer is covered by detailed and fast feedback unit tests with 100% of coverage. Although the layered architecture allowed me to mock other layers and write isolated unit tests for each layer as well, I preferred to cover Application, presentation, and infrastructure layers are by integration tests in order to have more valuable tests by having a higher chance of catching a regression.

Improvements

Exceptions are not handeled. There should be some improvements in Service class (application layer). BDD testing should be add to the project.