offloading: Add tests for offloading sink options

This commit adds tests to ensure proper configuration of sink options
when creating a bucket sink. The tests also validate that:
- Default values are correctly set.
- Special cases, such as WithNoRetry(), properly configure the
  configuration as expected.

internal/offloading/options_test.go

+package offloading
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestOffloadingSinkOptions(t *testing.T) {
+	t.Parallel()
+
+	for _, tc := range []struct {
+		desc        string
+		options     []SinkOption
+		expectedCfg sinkCfg
+	}{
+		{
+			desc: "with default values",
+			options: []SinkOption{
+				WithOverallTimout(defaultOverallTimeout),
+				WithMaxRetry(defaultMaxRetry),
+				WithRetryTimeout(defaultRetryTimeout),
+				WithBackoffStrategy(defaultBackoffStrategy),
+			},
+			expectedCfg: sinkCfg{
+				overallTimeout:  defaultOverallTimeout,
+				maxRetry:        defaultMaxRetry,
+				retryTimeout:    defaultRetryTimeout,
+				backoffStrategy: defaultBackoffStrategy,
+			},
+		},
+		{
+			desc: "with no backoffStrategy",
+			options: []SinkOption{
+				WithNoRetry(),
+			},
+			expectedCfg: sinkCfg{
+				maxRetry: 0,
+				noRetry:  true,
+			},
+		},
+		{
+			desc: "with customized values",
+			options: []SinkOption{
+				WithOverallTimout(20 * time.Second),
+				WithMaxRetry(100),
+				WithRetryTimeout(2 * time.Second),
+				WithBackoffStrategy(&backoffStrategyInTest),
+			},
+			expectedCfg: sinkCfg{
+				overallTimeout:  20 * time.Second,
+				maxRetry:        100,
+				retryTimeout:    2 * time.Second,
+				backoffStrategy: &backoffStrategyInTest,
+			},
+		},
+	} {
+		t.Run(tc.desc, func(t *testing.T) {
+			cfg := sinkCfg{}
+			for _, apply := range tc.options {
+				apply(&cfg)
+			}
+			require.Equal(t, tc.expectedCfg, cfg)
+		})
+	}
+}

internal/offloading/testhelper_test.go

+package offloading
+
+import (
+	"testing"
+
+	"gitlab.com/gitlab-org/gitaly/v16/internal/testhelper"
+)
+
+func TestMain(m *testing.M) {
+	testhelper.Run(m)
+}