vad4msiu / chartmogul_test

Installation

bundle install

Run

./bin/exporter --report-dir examples

Tests

bundle exec rspec

Task 1

The number will be any greater or equal than 100. It happens because operator select take the random ready channel and it can be ticker.C few times until select does not choose stopCh. To fix it we can prioritise select splitting it on two and use default case:

select {
    case <-stopCh:
        return
    default:
}
select {
    case <-ticker.C:
}

Task 2

I suggest changing the type of uuid column from text to uuid type and create indexes for external_id, uuid, another_id. The last one require because when there will be cascade deleting then it will scan the table for searching another_id.

Task 3

When we use some external API we need to worry about several things. First, it's a rate limit and pool of connections. Second, it's response errors.

With parallel importing, there can be a problem with sending the same request on create/retrieve customers and plans. There can be a performance problem and also a race condition problem. To avoid this we can use a runner with shared memory and mutex for updating this memory from workers. There can be also another solution and it really depends on how many reports we would like to import.