Testing

Karafka components work in isolation and are pretty simple. While testing, there are three crucial parts you should focus on:

Consumers and producers

We have a dedicated helper library for testing consumers and producers.

Please look at the karafka-testing README for details and examples.

Consumer groups and topics structure

Sometimes you may need to spec out your consumer groups and topics structure. To do so, simply access the Karafka::App.routes array and check everything you need. Here's an example of a Rspec spec that ensures a custom XmlDeserializer is being used to a xml_data topic from the batched_group consumer group:

RSpec.describe Karafka::App.routes do
  describe 'batched group' do
    let(:group) do
      Karafka::App.routes.find do |cg|
        cg.name == 'batched_group'
      end
    end

    describe 'xml_data topic' do
      let(:topic) { group.topics.find { |ts| ts.name == 'xml_data' } }

      it { expect(topic.deserializer).to eq XmlDeserializer }
    end
  end
end