fix: error check

Signed-off-by: Eray Ates <[email protected]>

error.go

@@ -41,6 +41,22 @@ func (e *DLQError) Error() string {
 	return "DLQ indexed error"
 }
 
+func (e *DLQError) Unwrap() error {
+	if e.Err == nil {
+		return ErrDLQ
+	}
+
+	if errors.Is(e.Err, ErrDLQ) {
+		return e.Err
+	}
+
+	return errors.Join(e.Err, ErrDLQ)
+}
+
+func (e *DLQError) IsZero() bool {
+	return e.Err == nil && len(e.Indexes) == 0
+}
+
 func WrapErrDLQ(err error) *DLQError {
 	return &DLQError{Err: err}
 }

error_test.go

@@ -1,6 +1,7 @@
 package wkafka
 
 import (
+	"errors"
 	"fmt"
 	"testing"
 
@@ -135,3 +136,17 @@ func Test_isDQLError(t *testing.T) {
 		})
 	}
 }
+
+func Test_isErr(t *testing.T) {
+	err := errors.New("testing")
+
+	checkErr := WrapErrDLQ(fmt.Errorf("some error: %w", err))
+
+	if !errors.Is(checkErr, err) {
+		t.Errorf("isErr() = %v, want %v", false, true)
+	}
+
+	if !errors.Is(checkErr, ErrDLQ) {
+		t.Errorf("isErr() = %v, want %v", false, true)
+	}
+}

producerdlq.go

@@ -15,15 +15,15 @@ func producerDLQ(topic string, clientID []byte, fn func(ctx context.Context, rec
 		recordsSend := make([]*kgo.Record, 0, len(records))
 
 		for i, r := range records {
-			errOrg := err.Err
+			errStr := err.Error()
 			if len(err.Indexes) > 0 {
 				errIndex, ok := err.Indexes[i]
 				if !ok {
 					continue
 				}
 
 				if errIndex != nil {
-					errOrg = errIndex
+					errStr = errIndex.Error()
 				}
 			}
 
@@ -34,7 +34,7 @@ func producerDLQ(topic string, clientID []byte, fn func(ctx context.Context, rec
 				Headers: append(
 					r.Headers,
 					kgo.RecordHeader{Key: "process", Value: clientID},
-					kgo.RecordHeader{Key: "error", Value: []byte(errOrg.Error())},
+					kgo.RecordHeader{Key: "error", Value: []byte(errStr)},
 					kgo.RecordHeader{Key: "offset", Value: []byte(strconv.FormatInt(r.Offset, 10))},
 					kgo.RecordHeader{Key: "partition", Value: []byte(strconv.FormatInt(int64(r.Partition), 10))},
 					kgo.RecordHeader{Key: "topic", Value: []byte(r.Topic)},