Fixup: Fix minor stuff

Author: martintomazic

go/oasis-node/cmd/storage/checkpoint.go

@@ -187,7 +187,7 @@ func newImportCmd() *cobra.Command {
 				for _, entry := range entries {
 					var ns common.Namespace
 					if err := ns.UnmarshalHex(entry.Name()); err != nil {
-						return fmt.Errorf("malformed source runtime ID: %q: %w", entry.Name(), err)
+						return fmt.Errorf("malformed source runtime ID: %s: %w", entry.Name(), err)
 					}
 					rtCpsDir := filepath.Join(runtimeInputDir, entry.Name())
 
@@ -226,14 +226,14 @@ func createCheckpoints(ctx context.Context, ndb api.NodeDB, ns common.Namespace,
 
 	roots, err := ndb.GetRootsForVersion(version)
 	if err != nil {
-		return fmt.Errorf("failed to get finalized roots %w", err)
+		return fmt.Errorf("failed to get roots %w", err)
 	}
 	if len(roots) == 0 {
 		// Empty roots are implicit in NodeDB and therefore not returned by GetRootsForVersion.
 		// If at this height state DB has an empty state, create a checkpoint for the empty state root,
 		// so that importing it will still finalize this version (making NodeDB non-empty).
 		//
-		// In case of state DB with with multiple empty roots (e.g. state and IO root both empty)
+		// In case of state DB with multiple empty roots (e.g. state and IO root both empty)
 		// this will create only one empty checkpoint (duplicate hash), which is safe as we only need
 		// it to finalize version with implicitly empty state and IO root.
 		stateRoot := node.Root{
@@ -247,7 +247,7 @@ func createCheckpoints(ctx context.Context, ndb api.NodeDB, ns common.Namespace,
 
 	creator, err := checkpoint.NewFileCreator(outputDir, ndb)
 	if err != nil {
-		return fmt.Errorf("failed to create checkpoint file creator: %w", err)
+		return fmt.Errorf("failed to create file creator: %w", err)
 	}
 
 	for _, root := range roots {
@@ -263,10 +263,10 @@ func createCheckpoints(ctx context.Context, ndb api.NodeDB, ns common.Namespace,
 func restoreCheckpoints(ctx context.Context, ndb api.NodeDB, ns common.Namespace, inputDir string) error {
 	isEmpty, err := isEmptyDir(inputDir)
 	if err != nil {
-		return fmt.Errorf("aborting checkpoint restoration: failed to inspect input directory: %w", err)
+		return fmt.Errorf("failed to inspect input directory: %w", err)
 	}
 	if isEmpty {
-		return fmt.Errorf("aborting checkpoint restoration: input directory is empty: %s", inputDir)
+		return fmt.Errorf("input directory is empty: %s", inputDir)
 	}
 	if _, ok := ndb.GetLatestVersion(); ok {
 		return fmt.Errorf("aborting checkpoint restoration: state db not empty")
@@ -550,21 +550,21 @@ func state(height uint64, stateStore cmtState.Store, blockStore *store.BlockStor
 }
 
 func isEmptyDir(dir string) (bool, error) {
-	// Over-engineering?
+	// Avoid using os.ReadDir as it reads the whole dir.
 	f, err := os.Open(dir)
 	if err != nil {
 		return false, fmt.Errorf("failed to open directory %q: %w", dir, err)
 	}
 	defer f.Close()
 
-	_, err = f.Readdir(1)
-	if errors.Is(err, io.EOF) {
-		return true, nil // empty
-	}
-	if err == nil {
+	switch _, err = f.Readdir(1); {
+	case err == nil:
 		return false, nil
+	case errors.Is(err, io.EOF):
+	default:
+		return false, fmt.Errorf("failed to read directory %q: %w", dir, err)
 	}
-	return false, fmt.Errorf("failed to read directory %q: %w", dir, err)
+	return true, nil
 }
 
 func ensureEmptyDir(dir string) error {

go/oasis-node/cmd/storage/checkpoint_test.go

@@ -286,7 +286,7 @@ func newTestNodeDB(t *testing.T, ns common.Namespace) (dbAPI.NodeDB, error) {
 	t.Helper()
 
 	return pathbadger.New(&dbAPI.Config{
-		DB:         filepath.Join(t.TempDir(), "db"),
+		DB:         filepath.Join(t.TempDir()),
 		Namespace:  ns,
 		MemoryOnly: true,
 	})
@@ -307,7 +307,8 @@ func commitRoot(
 	defer tree.Close()
 
 	for k, v := range data {
-		require.NoError(t, tree.Insert(ctx, []byte(k), []byte(v)))
+		err := tree.Insert(ctx, []byte(k), []byte(v))
+		require.NoError(t, err)
 	}
 
 	_, rootHash, err := tree.Commit(ctx, ns, version)