Add public local bundle writer

pkg/bundle/writer_integration_test.go

@@ -0,0 +1,38 @@
+package bundle_test
+
+import (
+	"bytes"
+	"context"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"gitea.maximumdirect.net/eric/distributor/internal/app"
+	"gitea.maximumdirect.net/eric/distributor/pkg/bundle"
+)
+
+func TestWriteBundleOutputValidatesThroughDistributor(t *testing.T) {
+	sourceRoot := t.TempDir()
+	outputRoot := filepath.Join(t.TempDir(), "bundle")
+	if err := os.WriteFile(filepath.Join(sourceRoot, "report.md"), []byte("# Report\n"), 0o600); err != nil {
+		t.Fatalf("write source: %v", err)
+	}
+
+	if _, err := bundle.WriteBundle(bundle.WriteBundleOptions{
+		Root: outputRoot,
+		ID:   "reports.distributor",
+		Files: []bundle.BundleFile{
+			{SourcePath: filepath.Join(sourceRoot, "report.md"), Path: "report.md"},
+		},
+	}); err != nil {
+		t.Fatalf("WriteBundle() error = %v", err)
+	}
+
+	var stdout bytes.Buffer
+	if err := app.Validate(context.Background(), app.ValidateOptions{Path: outputRoot, Stdout: &stdout}); err != nil {
+		t.Fatalf("app.Validate() error = %v", err)
+	}
+	if got, want := stdout.String(), "Validated 1 bundle(s)\n"; got != want {
+		t.Fatalf("stdout = %q, want %q", got, want)
+	}
+}