fix: pubsub ack must rely on protocol.IsAck

Signed-off-by: Nicolas Chapurlat <nc@coorganix.com>

protocol/pubsub/v2/message.go

@@ -14,6 +14,7 @@ import (
 	"github.com/cloudevents/sdk-go/v2/binding"
 	"github.com/cloudevents/sdk-go/v2/binding/format"
 	"github.com/cloudevents/sdk-go/v2/binding/spec"
+	"github.com/cloudevents/sdk-go/v2/protocol"
 )
 
 const (
@@ -120,14 +121,14 @@ func (m *Message) GetExtension(name string) interface{} {
 }
 
 // Finish marks the message to be forgotten.
-// If err is nil, the underlying Pubsub message will be acked;
-// otherwise nacked and return the error.
+// Regarding protocol.IsAck, the Pubsub message will be acked or not.
+// If not acked, the original error will be returned.
 func (m *Message) Finish(err error) error {
-	if err != nil {
-		m.internal.Nack()
-		return err
+	if protocol.IsACK(err) {
+		m.internal.Ack()
+		return nil
 	}
 
-	m.internal.Ack()
-	return nil
+	m.internal.Nack()
+	return err
 }

protocol/pubsub/v2/message_test.go

@@ -13,6 +13,7 @@ import (
 	"cloud.google.com/go/pubsub"
 	"github.com/cloudevents/sdk-go/v2/binding"
 	"github.com/cloudevents/sdk-go/v2/event"
+	"github.com/cloudevents/sdk-go/v2/protocol"
 )
 
 func TestReadStructured(t *testing.T) {
@@ -62,6 +63,22 @@ func TestFinish(t *testing.T) {
 			err:     fmt.Errorf("error"),
 			wantErr: true,
 		},
+		{
+			name: "result not acked",
+			pm: &pubsub.Message{
+				ID: "testid",
+			},
+			err:     protocol.NewReceipt(false, "error"),
+			wantErr: true,
+		},
+		{
+			name: "result acked",
+			pm: &pubsub.Message{
+				ID: "testid",
+			},
+			err:     protocol.NewReceipt(true, "error"),
+			wantErr: false,
+		},
 		{
 			name: "no errors",
 			pm: &pubsub.Message{