Define adapter interfaces and fake implementations

internal/adapters/storage/archive.go

@@ -0,0 +1,29 @@
+// Package storage declares archive/storage backend adapter boundaries.
+package storage
+
+import "context"
+
+// Backend is the adapter boundary for archive/storage operations.
+type Backend interface {
+	Archive(ctx context.Context, req ArchiveRequest) (ArchiveResult, error)
+}
+
+// ArchiveItem describes one item to archive.
+type ArchiveItem struct {
+	Kind      string
+	LocalPath string
+	RemoteKey string
+}
+
+// ArchiveRequest describes one archive operation.
+type ArchiveRequest struct {
+	SessionID    string
+	ManifestPath string
+	Items        []ArchiveItem
+}
+
+// ArchiveResult describes archive operation output.
+type ArchiveResult struct {
+	Archived []ArchiveItem
+	Metadata map[string]any
+}

internal/adapters/storage/fake.go

@@ -0,0 +1,40 @@
+package storage
+
+import "context"
+
+// NoopBackend is a deterministic no-op archive/storage adapter.
+type NoopBackend struct{}
+
+// Archive returns the requested items as archived with placeholder metadata.
+func (n *NoopBackend) Archive(ctx context.Context, req ArchiveRequest) (ArchiveResult, error) {
+	if err := ctx.Err(); err != nil {
+		return ArchiveResult{}, err
+	}
+	return ArchiveResult{Archived: append([]ArchiveItem(nil), req.Items...), Metadata: map[string]any{"placeholder": true}}, nil
+}
+
+// FakeBackend captures archive requests and returns deterministic responses.
+type FakeBackend struct {
+	Requests []ArchiveRequest
+	Err      error
+	Result   ArchiveResult
+}
+
+// Archive records request and returns configured response.
+func (f *FakeBackend) Archive(ctx context.Context, req ArchiveRequest) (ArchiveResult, error) {
+	if err := ctx.Err(); err != nil {
+		return ArchiveResult{}, err
+	}
+	f.Requests = append(f.Requests, req)
+	if f.Err != nil {
+		return ArchiveResult{}, f.Err
+	}
+	res := f.Result
+	if res.Archived == nil {
+		res.Archived = append([]ArchiveItem(nil), req.Items...)
+	}
+	if res.Metadata == nil {
+		res.Metadata = map[string]any{"fake": true}
+	}
+	return res, nil
+}

internal/adapters/storage/fake_test.go

@@ -0,0 +1,31 @@
+package storage
+
+import (
+	"context"
+	"errors"
+	"testing"
+)
+
+func TestFakeBackendCapturesRequestAndReturnsItems(t *testing.T) {
+	fake := &FakeBackend{}
+	req := ArchiveRequest{SessionID: "s1", Items: []ArchiveItem{{Kind: "artifact", LocalPath: "artifacts/log.md"}}}
+
+	res, err := fake.Archive(context.Background(), req)
+	if err != nil {
+		t.Fatalf("Archive() error = %v", err)
+	}
+	if len(fake.Requests) != 1 || fake.Requests[0].SessionID != "s1" {
+		t.Fatalf("requests = %#v, want captured request", fake.Requests)
+	}
+	if len(res.Archived) != 1 {
+		t.Fatalf("archived len = %d, want 1", len(res.Archived))
+	}
+}
+
+func TestFakeBackendError(t *testing.T) {
+	fake := &FakeBackend{Err: errors.New("boom")}
+	_, err := fake.Archive(context.Background(), ArchiveRequest{})
+	if err == nil {
+		t.Fatal("expected error, got nil")
+	}
+}