How should I start

1. install required dependencies by running the bundle install command
2. create the database using the rake db:create command
3. apply migrations to the database using the rake db:migrate command
4. run tests by executing the bin/rails test -v command
5. run the bin/rails server command to see whether the server starts

Scenario

Let’s imagine you are working on API for backend of an online payment system. The actors are: users (festival participants), merchants, event organiser. We want to enable backoffice operations to the event organiser.

Currently implemented:

• Users can make a payment (with a virtual currency) to a specific merchant.
• Our system has a payment log.
• It means that information about payments are stored in a database.
• This data can be used for reporting.

Tasks

Task 1:

Please make a code review of the currently implemented solution.

Task 2:

Add new endpoint which give total income for payments for selected time period for given merchant.