test: add producer tests

producer.go

@@ -12,8 +12,13 @@ type Producer interface {
 	Close() error
 }
 
+type Writer interface {
+	WriteMessages(context.Context, ...kafka.Message) error
+	Close() error
+}
+
 type producer struct {
-	w *kafka.Writer
+	w Writer
 }
 
 func NewProducer(cfg ProducerConfig) (Producer, error) {

producer_config.go

@@ -42,7 +42,7 @@ type ProducerConfig struct {
 	Writer    WriterConfig
 }
 
-func (c ProducerConfig) newKafkaWriter() (*kafka.Writer, error) {
+func (c ProducerConfig) newKafkaWriter() (Writer, error) {
 	kafkaWriter := &kafka.Writer{
 		Addr:                   kafka.TCP(c.Writer.Brokers...),
 		Topic:                  c.Writer.Topic,

producer_test.go

@@ -0,0 +1,57 @@
+package kafka
+
+import (
+	"context"
+	"testing"
+
+	"github.com/segmentio/kafka-go"
+)
+
+func Test_producer_Produce_Successfully(t *testing.T) {
+	// Given
+	mw := &mockWriter{}
+	p := producer{w: mw}
+
+	// When
+	err := p.Produce(context.Background(), Message{})
+	// Then
+	if err != nil {
+		t.Fatalf("Producing err %s", err.Error())
+	}
+}
+
+func Test_producer_ProduceBatch_Successfully(t *testing.T) {
+	// Given
+	mw := &mockWriter{}
+	p := producer{w: mw}
+
+	// When
+	err := p.ProduceBatch(context.Background(), []Message{{}, {}, {}})
+	// Then
+	if err != nil {
+		t.Fatalf("Batch Producing err %s", err.Error())
+	}
+}
+
+func Test_producer_Close_Successfully(t *testing.T) {
+	// Given
+	mw := &mockWriter{}
+	p := producer{w: mw}
+
+	// When
+	err := p.Close()
+	// Then
+	if err != nil {
+		t.Fatalf("Closing err %s", err.Error())
+	}
+}
+
+type mockWriter struct{}
+
+func (m *mockWriter) WriteMessages(ctx context.Context, message ...kafka.Message) error {
+	return nil
+}
+
+func (m *mockWriter) Close() error {
+	return nil
+}