Add remote storage backend

internal/adapters/storage/factory_test.go

@@ -0,0 +1,56 @@
+package storage
+
+import (
+	"context"
+	"strings"
+	"testing"
+
+	"gitea.maximumdirect.net/eric/narratio/internal/config"
+)
+
+func TestNewObjectStoreFromConfigBuildsS3WhenBackendIsS3(t *testing.T) {
+	original := newS3Client
+	t.Cleanup(func() { newS3Client = original })
+	newS3Client = func(_ context.Context, _ s3ClientOptions) (s3API, error) {
+		return &fakeS3API{}, nil
+	}
+
+	store, err := NewObjectStoreFromConfig(context.Background(), &config.Config{
+		Pipeline: &config.PipelineConfig{
+			Storage: config.StorageConfig{
+				Backend: "s3",
+				S3: &config.StorageS3Config{
+					Bucket: "my-archive",
+				},
+			},
+		},
+	})
+	if err != nil {
+		t.Fatalf("NewObjectStoreFromConfig() error = %v", err)
+	}
+	if _, ok := store.(*S3Backend); !ok {
+		t.Fatalf("store type = %T, want *S3Backend", store)
+	}
+}
+
+func TestNewObjectStoreFromConfigRequiresS3ConfigWhenBackendIsS3(t *testing.T) {
+	_, err := NewObjectStoreFromConfig(context.Background(), &config.Config{
+		Pipeline: &config.PipelineConfig{
+			Storage: config.StorageConfig{Backend: "s3"},
+		},
+	})
+	if err == nil || !strings.Contains(err.Error(), "pipeline.storage.s3 is required") {
+		t.Fatalf("NewObjectStoreFromConfig() error = %v, want missing storage.s3 error", err)
+	}
+}
+
+func TestNewObjectStoreFromConfigNoRemoteBackendConfigured(t *testing.T) {
+	_, err := NewObjectStoreFromConfig(context.Background(), &config.Config{
+		Pipeline: &config.PipelineConfig{
+			Storage: config.StorageConfig{Backend: "local"},
+		},
+	})
+	if err == nil || !strings.Contains(err.Error(), "no remote object store backend is configured") {
+		t.Fatalf("NewObjectStoreFromConfig() error = %v, want no-backend error", err)
+	}
+}