The goal of this challenge is to create an API that can be used to compute the Belgium driver's bonus-malus score. This score depends on the number of driving years, the number of accidents and the driving usage. The score is in the range -2 (best) to 22 (worst).

The project has the following structure:

• domain/ => contains the business logic
• api/graphql/ => contains the graphql api
• cmd/server/ => contains the entry point of this application
• Dockerfile => a multi-stage build dockerfile used to build & run the application
• Makefile => a makefile to simplify developpement

I chose to use the DDD pattern as it focuses on creating a shared understanding of the problem domain between technical and non-technical team members. This approach also facilitates the modularity and readability of the code.

GraphQL provides a powerful and flexible query language for fetching data. It has many advantages but it is definitely overkill for such small usecase. The only real reason to implement a GraphQL API here is pure fun.

A simple & powerful library for building GraphQL servers. More at https://gqlgen.com/.

To update the GraphQL schema, you will need to modify the api/graphql/schema.graphqls file. It is then necessary to re-generate code associated to this schema using:

make generate

To run the application, you will need to install on your machine:

• docker
• make

To test and lint, you will need to install on your machine:

• go >= 1.21
• golangci-lint

The easiest way to run this application is via docker.

make run

This application exposes a GraphQL API at http://localhost:8080/query by default. You can manually interact with the API using the built-in GraphQL playground at http://localhost:8080/.

There is only one query available, bonusMalusScore which returns the bonus-malus score as an integer. Further user documentation can be retrieved from the GraphQL schema accessible on the playground.

You can test the application using:

make test

You can lint the code using:

make lint

• Improve this README
• Run tests in CI as a github action
• Convert bonusMalusScore query parameters to uint