Accounting API

Application provide RESTful API for inserting transactions related to account and accessing its balance.

Design

Transactions are appended to history table, actual balance can be accessed via view that aggregates history. Application heavily relies on IO monad and effects. Application uses hexagon architecture pattern.

Application provides two types of backend:

• inmemory hashmap
• h2 database

Main frameworks used:

• http4s - http layer
• doobie - database access layer
• flyway - schema migration logic
• circe - json manipulation
• h2 - inmemory database

End points

The end points are:

Method	Url	Description
GET	/balance/{id}	Returns balance of account
POST	/transactions	Process list of transactions
GET	/build-info	Deployed application meta

How To

Create a transactions: curl -X POST --header "Content-Type: application/json" --data '[{"id": 1, "delta": 100}]' http://localhost:4140/transactions

Get account balance: curl http://localhost:4140/balance/1

Get account balance: curl http://localhost:4140/build-info

Run Application

Default http port used in application: 4140. Updated application.conf in order to modify it or via environment variable HTTP_PORT Application can started by:

• RECOMMENDED sbt assembly and java -jar app.jar. Latest assembled version of application are in root of repository
• sbt docker and cd deployment; docker-compose up
• SIMPLEST sbt run, may have potential issues with applying migrations resolved with sbt version 1.1.0

Issue log output:

2018-10-19 09:31:19 [scala-execution-context-global-93] WARN  o.f.c.i.u.s.c.ClassPathScanner - Unable to resolve location classpath:db/migration