Module: Karafka::Testing::Minitest::Helpers

Defined in:
lib/karafka/testing/minitest/helpers.rb

Overview

Minitest helpers module that needs to be included

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.included(base) ⇒ Object

Adds all the needed extra functionalities to the minitest group

Parameters:

  • base (Class) —

    Minitest example group we want to extend



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# File 'lib/karafka/testing/minitest/helpers.rb', line 19

def included(base)
  eval_flow = lambda do
    @karafka = Karafka::Testing::Minitest::Proxy.new(self)
    @_karafka_consumer_messages = []
    @_karafka_consumer_client = Karafka::Testing::SpecConsumerClient.new
    @_karafka_producer_client = Karafka::Testing::SpecProducerClient.new(self)

    @_karafka_consumer_messages.clear
    @_karafka_producer_client.reset

    Karafka.producer.stubs(:client).returns(@_karafka_producer_client)
  end

  if base.to_s == 'Minitest::Spec'
    base.class_eval do
      before(&eval_flow)
    end
  else
    base.class_eval do
      setup(&eval_flow)
    end
  end
end

Instance Method Details

#_karafka_add_message_to_consumer_if_needed(message) ⇒ Object

Adds a new Karafka message instance if needed with given payload and options into an internal consumer buffer that will be used to simulate messages delivery to the consumer

Examples:

Send a json message to consumer

@karafka.produce({ 'hello' => 'world' }.to_json)

Send a json message to consumer and simulate, that it is partition 6

@karafka.produce({ 'hello' => 'world' }.to_json, 'partition' => 6)

Parameters:

  • message (Hash) —

    message that was sent to Kafka



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# File 'lib/karafka/testing/minitest/helpers.rb', line 78

def _karafka_add_message_to_consumer_if_needed(message)
  # Consumer needs to be defined in order to pass messages to it
  return unless defined?(@consumer)
  # We're interested in adding message to consumer only when it is a Karafka consumer
  # Users may want to test other things (models producing messages for example) and in
  # their case consumer will not be a consumer
  return unless @consumer.is_a?(Karafka::BaseConsumer)
  # We target to the consumer only messages that were produced to it, since specs may also
  # produce other messages targeting other topics
  return unless message[:topic] == @consumer.topic.name

  # Build message metadata and copy any metadata that would come from the message
  metadata = _karafka_message_metadata_defaults

  metadata.keys.each do |key|
    next unless message.key?(key)

    metadata[key] = message.fetch(key)
  end
  # Add this message to previously produced messages
  @_karafka_consumer_messages << Karafka::Messages::Message.new(
    message[:payload],
    Karafka::Messages::Metadata.new(metadata).freeze
  )
  # Update batch metadata
  batch_metadata = Karafka::Messages::Builders::BatchMetadata.call(
    @_karafka_consumer_messages,
    @consumer.topic,
    0,
    Time.now
  )

  # Update consumer messages batch
  @consumer.messages = Karafka::Messages::Messages.new(
    @_karafka_consumer_messages,
    batch_metadata
  )
end

#_karafka_consumer_for(requested_topic, requested_consumer_group = nil) ⇒ Object

Creates a consumer instance for a given topic

Examples:

Creates a consumer instance with settings for my_requested_topic

consumer = @karafka.consumer_for(:my_requested_topic)

Parameters:

  • requested_topic (String, Symbol) —

    name of the topic for which we want to create a consumer instance

  • requested_consumer_group (String, Symbol, nil) (defaults to: nil) —

    optional name of the consumer group if we have multiple consumer groups listening on the same topic

Returns:

  • (Object) —

    Karafka consumer instance

Raises:



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# File 'lib/karafka/testing/minitest/helpers.rb', line 56

def _karafka_consumer_for(requested_topic, requested_consumer_group = nil)
  selected_topics = Testing::Helpers.karafka_consumer_find_candidate_topics(
    requested_topic.to_s,
    requested_consumer_group.to_s
  )

  raise Errors::TopicInManyConsumerGroupsError, requested_topic if selected_topics.size > 1
  raise Errors::TopicNotFoundError, requested_topic if selected_topics.empty?

  _karafka_build_consumer_for(selected_topics.first)
end

#_karafka_produce(payload, metadata = {}) ⇒ Object

Produces message with a given payload to the consumer matching topic

Parameters:

  • payload (String) —

    payload we want to dispatch

  • metadata (Hash) (defaults to: {}) —

    any metadata we want to dispatch alongside the payload



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# File 'lib/karafka/testing/minitest/helpers.rb', line 120

def _karafka_produce(payload, metadata = {})
  Karafka.producer.produce_sync(
    {
      topic: @consumer.topic.name,
      payload: payload
    }.merge(metadata)
  )
end

#_karafka_produced_messages ⇒ Array<Hash>

Returns messages that were produced.

Returns:

  • (Array<Hash>) —

    messages that were produced



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# File 'lib/karafka/testing/minitest/helpers.rb', line 130

def _karafka_produced_messages
  @_karafka_producer_client.messages
end