Basic REST API written in Kotlin
This is a very basic REST API with a single resource written in Kotlin. The project has 94% test coverage (I don't test config code and usually aim for 80%).
Store
{
"id": "5e989e63aea74d64e63709f9",
"name": "Store 8",
"address": "132 High St",
"phone": "3039987473",
"status": "OPEN"
}Dependencies used:
- Spring Boot 2.2.6
- JUnit 5
- Mockito
- Spring Web(MVC)
- Spring Data MongoDB
- MapStruct
- Lombok
The project needs an unsecured MongoDB instance running on localhost with the default port. If you have docker just use the following command:
docker run -d -p 27017:27017 --name mongodb -v ~/data:/data/db mongo:4.2.3
Then you can either launch the application in your IDE, or use Maven to create a jar and execute the jar.
The project includes a Postman collection you can use to exercise the API in the postman folder.
Historically, your typical package structure has looked like this:
|- exception
|- repository
|- service
|- controller
|- util
A structure like the one above means that changes usually end up spanning multiple packages. Instead, I prefer to have a package for each feature group or bounded context. The repository, service, controller, and all related files live in the same package which helps with readability, and a step toward isolated (loosely coupled, highly cohesive) components. Most methods can also be package protected instead of public forcing us to be explicit about what we need to expose to other parts of the application. This structure also makes it much easier to break out a microservice if/when this is deemed necessary.
|- exception
|- store
|- order
|- shipping
Notice we don't have a util package(code smell)!
The exception package and it's tests have no dependencies on the other packages and could easily be pulled into some common jar or even a dedicated exception handling lib.
It handles most bad input/bad request related exceptions and shapes them into meaningful responses, including sending back valid values for any invalid Enum.