Flow Currency Rates

Assignment description

You can run the solution by cloning this repository and executing sbt run Press Return to stop the app.

Application provides a basic index page with example endpoint invocations on http://localhost:9000/

API

Exposed API contains only GET requests and query parameters so it's convenient to use from a browser. Fixer platform connectivity is established under the hood - one can override used Fixer Access Key by setting FIXER_ACCESS_KEY env variable.

Currency rates endpoints

• http://localhost:9000/rates?base=USD
• http://localhost:9000/rates?base=USD&target=CAD
• http://localhost:9000/rates?base=USD&timestamp=2016-05-01T14:34:46Z
• http://localhost:9000/rates?base=USD&target=CAD&timestamp=2016-05-01T14:34:46Z

Currency rates monitoring

• http://localhost:9000/monitoring - lists all currently monitored currency rates
• http://localhost:9000/monitoring/start?currency=USD - starts monitoring currency rates for USD
• http://localhost:9000/monitoring/stop?currency=USD - stops monitoring currency rates for USD

Libraries used

• Akka HTTP - faster than Play Framework; there was no need to use for example templates, forms, database support etc
• Akka Streams - ideal for endless source of data like a loop of currency rate requests for monitoring
• WireMock - mock http server for unit tests
• Mockito - useful methods for verifying interactions between the test objects
• Play JSON - personal taste :)