What it is?

This is package having sarama.ConsumerGroup mock.

It is faking kafka partitions consuming allowing unit testing.

How to use it?

1. In production code define following instead of using sarama.NewConsumerGroup directly:

   // NewConsumerGroup is abstracting the sarama interfaces in order to do better unit testing.
   type NewConsumerGroup func(addrs []string, groupID string, config *sarama.Config) (sarama.ConsumerGroup, error)
   

2. In your init-code use sarama.NewConsumerGroup function as implementation of that interface.

3. In unit tests do following to initialize the mock :

   config := mocks.NewTestConfig()
   cg, err := cgmocks.NewConsumerGroup([]string{"localhost"}, "testGroupID", config)
   assert.NoError(t, err)
   fnc := func(addrs []string, groupID string, config *sarama.Config) (sarama.ConsumerGroup, error) {
       return cg, nil
   }
   // TODO pass fnc to your production code init instead of sarama.NewConsumerGroup
   

4. In unit test first define which topic-partition to fake subscription to and then pass the messages you want to be read from:

   claim1 := mockCG.YeldNewClaim(conf.Topics[0], 1, 0)
   claim1.YeldMessage4("{\"status\":\"ongoing\",\"operationId\":\"1234567890\"}")
   

   After that your code will receive this message in ConsumerGroupClaim.Messages() channel.