System architecture

Microservices architecture

The microservices are structured in layers:

• Domain: implementation of the domain entities according to DDD
• Repository: encapsulation of the access and management of the database according to DDD
• Application: encapsulation of the services and the business logic according to DDD
• Handler: management of http requests
• API: exposed by routes in menu-service and orders-service, exposed by server in WarehouseService

Testing

Concerning WarehouseService, the structure of the test follows the structure of the microservice. We have JUnit tests for Repository, Application and Server and we have also Cucumber tests for the repository layer.
For menu-service we test routes using Jest.
For orders-service we test repository and routes using Jest

Server architecture

Server is the component that maps the messages arriving from the front-end application, via web socket, to the APIs exposed by the microservices.

For many APIs, once one of them has been called, the server simply waits for the response and sends it back.

In some cases, the server job is to manage the interactions between the microservices for those functionalities that are implemented relying on more than one API calls. It decides the order of the requests, waits for their responses and, based on the results, manages the next step dealing with errors if needed.