Description

A Restful Web-API that calculates IRR and APR for a given loan, the loan installments as well as the interest fee does not have to be fixed amounts

Running locally

sbt reStart

After the server is up, use your favorite client to make a POST call to the endpoint http://localhost:8080/calculation with a given loan

Caveats

• You can use the input part of the example provided in example.json
• Paste the contents of api.yaml on https://editor.swagger.io for a visual representation of the API components

Disclaimer

It is important to mention that the method to calculate the IRR and APR are drawn completely from various online resources and mildly adapted to Scala from Java, which is obvious by the apparent non-idiomatic algorithm to calculate the IRR

Developer guide

The application uses Http4s as an http server, with its dependencies cats, cats-effects, circe and specs2 for testing

Making use of the IO monad to encode the results of the computation as well as stack side effects and failures.

The application follows an MVC-like paradigm, where it exists

• An http layer handles the queries
• A services layer handles the computation
• A models layer to handle application models as well as json marshalling/unmarshalling
• Additional utilities, Error, httpErrorHandler does error transformation and handling and utlitiary functions/models

Testing

Unit tests were written for each of the functional components using specs2 library

To run the unit tests, type the following command in your terminal

sbt test

Future Improvements

• Better Logging modules and functional logging
• Scenario and integration tests
• Contribution guidelines and better architectural documentation
• Performance analysis and JVM profiling
• Better, idiomatic approach to calculating IRR and APR instead of the existing one