GoLang Sarama ConsumerGroup Mocking

Question

I am new to Go and I am struggling to mock out the call too: sarama.NewConsumerGroup(brokers, group, config)

I am using testify and my mocked code currently looks like:

type MyMockedObjectReciever struct {
    mock.Mock
    Receiver
}

func (m *MyMockedObjectReciever) mockCreateConsumer(brokers []string, group string, config *sarama.Config) (sarama.ConsumerGroup, error) {
    args := m.Called(brokers, group, config)
    return args.Get(0).(sarama.ConsumerGroup), args.Error(1)
}

// mock connection and subscribe
        wantConsumer := sarama.NewConsumerGroup
        createConsumer = c.mockCreateConsumer
        c.On("mockCreateConsumer", []string{testBrokers}, testGroup, wantConfig).Return(wantConsumer, nil).Once()

But I get the error:

--- FAIL: TestKafkaReceiver (0.00s)
    --- FAIL: TestKafkaReceiver/test_a_Kafka_receiver (0.00s)
panic: interface conversion: func([]string, string, *sarama.Config) (sarama.ConsumerGroup, error) is not sarama.ConsumerGroup: missing method Close [recovered]
    panic: interface conversion: func([]string, string, *sarama.Config) (sarama.ConsumerGroup, error) is not sarama.ConsumerGroup: missing method Close

I beleive I am mocking the call incorrectly but now sure what else to do.

score 1 · Accepted Answer · answered Jun 18 '20 at 00:45

You could write your mock consumer like this below which will satisfy the consumergroup object.

// Consumergroup handler
type testConsumerGroupHandler struct {
}

func (C testConsumerGroupHandler) Consume(ctx context.Context, topics []string, handler sarama.ConsumerGroupHandler) error {
    return nil
}
func (C testConsumerGroupHandler) Errors() <-chan error {
    return nil
}
func (C testConsumerGroupHandler) Close() error {
    return nil
}

Afterwards, you should write your methods for success and failure and accordingly setup mock testing

GoLang Sarama ConsumerGroup Mocking

1 Answers1