Make a mistyped subcommand under a group command an error (closes #319)

snapshot, config, remote, database and completion had no Run, and
cobra checks a command's arguments only when it has one, so `vaultik
snapshot craete` printed the group's help and exited 0. Each group now
prints its help only when given no argument; any other word fails as
an unknown command with exit 1, as at the top level.

cobra adds the completion command only when Execute runs, so the root
command now adds it itself to give it a Run. Its scripts then go to
os.Stdout as it was at that moment; a later SetOut does not redirect
them.

Judgement call: the error has no "Did you mean" suggestion, which the
top level gives.

Model: opus-5-5

README.md

@@ -286,7 +286,9 @@ needed.
   remove orphaned blobs from remote storage. By default keeps only the latest
   snapshot per name; use `--keep-newer-than` for a rolling window.
 * `--keep-newer-than <duration>`: With `--prune`, keep snapshots newer than
-  this duration instead of only the latest (e.g. `4w`, `30d`, `6mo`, `1y`)
+  this duration instead of only the latest (e.g. `4w`, `30d`, `6mo`, `1y`).
+  Without `--prune`, or with a value that is not a valid duration, the
+  command fails before the backup starts.
 
 **`snapshot list`**: Show every snapshot known to this host — the union
 of the local index and the backup destination store — with timestamps

TODO.md

@@ -22,17 +22,6 @@ the tag exists and is exercised; what is left is merging `next` to
 
 # Completed Steps
 
-- 2026-10-13: Made a `file://` destination list through a symlinked
-  directory ([issue #296](https://git.eeqj.de/sneak/vaultik/issues/296)).
-  A `metadata/` or `blobs/` directory that was a symlink to a directory
-  elsewhere was listed as one file, so the destination store listed as
-  empty while backups and restores still worked through the link.
-  `prune` then removed the local snapshot records and deleted every blob,
-  and `remote info` and `remote nuke` found no blobs. The listings now
-  read through the link as `Get` and `Stat` do. A link whose target is
-  missing, such as one to a volume that is not mounted, or a link
-  pointing back up the tree makes them fail.
-
 - 2026-10-13: Stopped `remote info` counting a file under `blobs/` that
   is not a blob as an orphaned blob
   ([issue #295](https://git.eeqj.de/sneak/vaultik/issues/295)). A stray

internal/blob/packer.go

@@ -245,6 +245,17 @@ func (p *Packer) Flush(ctx context.Context) error {
 	return nil
 }
 
+// DiscardCurrentBlob closes and removes the temp file of the blob being
+// packed, if any, and drops that blob. A caller that stops before Flush
+// must call it, or the temp file is left behind. Thread-safe.
+func (p *Packer) DiscardCurrentBlob() {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+
+	p.cleanupTempFile()
+	p.currentBlob = nil
+}
+
 // FinalizeBlob finalizes the current blob being assembled.
 // This compresses the accumulated chunks, encrypts the result, and computes
 // the content-addressed hash. The finalized blob is either passed to the

internal/cli/config.go

@@ -251,6 +251,12 @@ func NewConfigCommand() *cobra.Command {
 		Use:   "config",
 		Short: "Manage the configuration file",
 		Long:  "Commands for creating, editing, and querying the vaultik config file.",
+		// cobra checks Args only on a command that has a Run: without
+		// one, a mistyped subcommand printed help and exited 0.
+		Args: cobra.NoArgs,
+		Run: func(cmd *cobra.Command, _ []string) {
+			_ = cmd.Help()
+		},
 	}
 
 	cmd.AddCommand(newConfigInitCommand())

internal/cli/database.go

@@ -15,6 +15,12 @@ func NewDatabaseCommand() *cobra.Command {
 		Use:   "database",
 		Short: "Manage the local state database",
 		Long:  `Commands for managing the local SQLite state database.`,
+		// cobra checks Args only on a command that has a Run: without
+		// one, a mistyped subcommand printed help and exited 0.
+		Args: cobra.NoArgs,
+		Run: func(cmd *cobra.Command, _ []string) {
+			_ = cmd.Help()
+		},
 	}
 
 	cmd.AddCommand(

internal/cli/entry_snapshot_create_prune_test.go

@@ -0,0 +1,108 @@
+package cli //nolint:testpackage // shares runEntry and the hermetic config helpers
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// Flags of `snapshot create` used to build argument vectors below.
+const (
+	flagPrune         = "--prune"
+	flagKeepNewerThan = "--keep-newer-than"
+)
+
+// TestEntrySnapshotCreateRejectsKeepNewerThanBeforeBackup checks that a
+// --keep-newer-than the post-backup prune could not use stops `snapshot
+// create` before the backup: the command fails and the destination
+// store stays empty. It used to be read only by the prune, after the
+// snapshot was uploaded, and without --prune it was ignored.
+//
+//nolint:paralleltest // replaces os.Args, os.Stdout, os.Stderr and the xdg globals
+func TestEntrySnapshotCreateRejectsKeepNewerThanBeforeBackup(t *testing.T) {
+	for _, testCase := range []struct {
+		name string
+		args []string
+	}{
+		{
+			name: "decimal in a day count",
+			args: []string{flagPrune, flagKeepNewerThan, "1.5d"},
+		},
+		{
+			name: "unknown unit",
+			args: []string{flagPrune, flagKeepNewerThan, "4x"},
+		},
+		{
+			name: "without --prune",
+			args: []string{flagKeepNewerThan, "4w"},
+		},
+	} {
+		t.Run(testCase.name, func(t *testing.T) {
+			configPath, storeDir := writeBackupConfig(t)
+
+			code, _, _ := runEntry(t, append(
+				[]string{flagConfig, configPath, cmdSnapshot, cmdCreate},
+				testCase.args...)...)
+
+			assert.Equal(t, 1, code)
+
+			stored, err := os.ReadDir(storeDir)
+			require.NoError(t, err)
+			assert.Empty(t, stored, "nothing may be uploaded")
+		})
+	}
+}
+
+// TestEntrySnapshotCreateReportsPostBackupPruneFailure makes the
+// post-backup prune fail after a good backup, by planting a manifest
+// that cannot be decoded, and checks that the failure is reported as the
+// prune's and not as a failed snapshot creation.
+//
+//nolint:paralleltest // replaces os.Args, os.Stdout, os.Stderr and the xdg globals
+func TestEntrySnapshotCreateReportsPostBackupPruneFailure(t *testing.T) {
+	configPath, storeDir := writeBackupConfig(t)
+
+	// A remote key is 64 lowercase hex characters. The prune reads every
+	// manifest on the store and fails on one it cannot decode.
+	plantedDir := filepath.Join(storeDir, "metadata", strings.Repeat("a", 64))
+	require.NoError(t, os.MkdirAll(plantedDir, 0o750))
+	require.NoError(t, os.WriteFile(
+		filepath.Join(plantedDir, "manifest.json.zst"),
+		[]byte("not a valid manifest"), 0o600))
+
+	code, _, stderr := runEntry(t,
+		flagConfig, configPath, cmdSnapshot, cmdCreate, flagPrune)
+
+	assert.Equal(t, 1, code)
+	assert.Contains(t, stderr, "Backup completed, but post-backup prune failed")
+	assert.NotContains(t, stderr, "Snapshot creation failed")
+
+	snapshots, err := os.ReadDir(filepath.Join(storeDir, "metadata"))
+	require.NoError(t, err)
+	assert.Len(t, snapshots, 2,
+		"the new snapshot is on the store beside the planted one")
+}
+
+// writeBackupConfig builds a hermetic config with one small file in its
+// source directory and an empty destination store directory. Returns the
+// config path and the store directory.
+func writeBackupConfig(t *testing.T) (string, string) {
+	t.Helper()
+
+	configPath := writeHermeticPruneConfig(t, false)
+
+	// writeHermeticPruneConfig puts the source and store directories
+	// beside the config file.
+	dir := filepath.Dir(configPath)
+	sourceDir := filepath.Join(dir, "source")
+
+	require.NoError(t, os.Mkdir(sourceDir, 0o750))
+	require.NoError(t, os.WriteFile(
+		filepath.Join(sourceDir, "file.txt"), []byte("hello"), 0o600))
+
+	return configPath, filepath.Join(dir, "store")
+}

internal/cli/entry_unknown_subcommand_test.go

@@ -0,0 +1,43 @@
+package cli //nolint:testpackage // shares runEntry and the command-word constants
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+// TestEntryGroupRejectsUnknownSubcommand runs each group command with a
+// mistyped subcommand, as a crontab line might carry one. It must fail
+// with exit 1 and name the word, as `vaultik bogus` does at the top
+// level, instead of printing the group's help and exiting 0 having done
+// nothing. The group name alone still prints its help.
+//
+//nolint:paralleltest // replaces os.Args, os.Stdout and os.Stderr
+func TestEntryGroupRejectsUnknownSubcommand(t *testing.T) {
+	for _, testCase := range []struct {
+		group    string
+		mistyped string
+	}{
+		{group: cmdSnapshot, mistyped: "craete"},
+		{group: "config", mistyped: "inti"},
+		{group: cmdRemote, mistyped: "ifno"},
+		{group: "database", mistyped: "delte"},
+		{group: "completion", mistyped: "nosuchshell"},
+	} {
+		t.Run(testCase.group, func(t *testing.T) {
+			code, stdout, stderr := runEntry(t,
+				testCase.group, testCase.mistyped)
+
+			assert.Equal(t, 1, code)
+			assert.Empty(t, stdout)
+			assert.Contains(t, stderr,
+				`unknown command "`+testCase.mistyped+`"`)
+
+			code, stdout, _ = runEntry(t, testCase.group)
+
+			assert.Equal(t, 0, code)
+			assert.Contains(t, stdout,
+				programName+" "+testCase.group+" [command]")
+		})
+	}
+}

internal/cli/remote.go

@@ -18,6 +18,12 @@ func NewRemoteCommand() *cobra.Command {
 		Use:   "remote",
 		Short: "Remote storage management commands",
 		Long:  "Commands for inspecting and managing remote storage",
+		// cobra checks Args only on a command that has a Run: without
+		// one, a mistyped subcommand printed help and exited 0.
+		Args: cobra.NoArgs,
+		Run: func(cmd *cobra.Command, _ []string) {
+			_ = cmd.Help()
+		},
 	}
 
 	// Add subcommands

internal/cli/root.go

@@ -74,6 +74,21 @@ on the source system.`,
 		NewDatabaseCommand(),
 	)
 
+	// cobra adds the completion command only when Execute runs, and with
+	// no Run, so it skipped its own cobra.NoArgs and a mistyped shell name
+	// printed help and exited 0. Adding it here lets it have a Run. Its
+	// scripts go to os.Stdout as it is now: a later SetOut does not
+	// redirect them.
+	cmd.InitDefaultCompletionCmd()
+
+	for _, sub := range cmd.Commands() {
+		if sub.Name() == "completion" {
+			sub.Run = func(completion *cobra.Command, _ []string) {
+				_ = completion.Help()
+			}
+		}
+	}
+
 	return cmd
 }
 

internal/cli/snapshot.go

@@ -41,6 +41,12 @@ func NewSnapshotCommand() *cobra.Command {
 		Use:   "snapshot",
 		Short: "Snapshot management commands",
 		Long:  "Commands for creating, listing, and managing snapshots",
+		// cobra checks Args only on a command that has a Run: without
+		// one, a mistyped subcommand printed help and exited 0.
+		Args: cobra.NoArgs,
+		Run: func(cmd *cobra.Command, _ []string) {
+			_ = cmd.Help()
+		},
 	}
 
 	// Add subcommands
@@ -71,6 +77,11 @@ otherwise from the platform config directory (~/.config/vaultik/config.yml
 on Linux), then /etc/vaultik/config.yml.`,
 		Args: cobra.ArbitraryArgs,
 		RunE: func(cmd *cobra.Command, args []string) error {
+			err := opts.Validate()
+			if err != nil {
+				return err
+			}
+
 			// Pass snapshot names from args
 			opts.Snapshots = args
 			// --skip-errors is a global flag on the root command.
@@ -97,6 +108,13 @@ on Linux), then /etc/vaultik/config.yml.`,
 			}, func(v *vaultik.Vaultik) error {
 				return v.CreateSnapshot(opts)
 			}, func(err error) {
+				if errors.Is(err, vaultik.ErrPostBackupPruneFailed) {
+					log.Error("Post-backup prune failed", "error", err)
+					ReportErrorf("Backup completed, but %v", err)
+
+					return
+				}
+
 				log.Error("Snapshot creation failed", "error", err)
 				ReportErrorf("Snapshot creation failed: %v", err)
 			})

internal/snapshot/scanner.go

@@ -1295,6 +1295,11 @@ func (s *Scanner) batchAddFilesToSnapshot(
 func (s *Scanner) processPhase(
 	ctx context.Context, filesToProcess []*FileToProcess, result *ScanResult,
 ) error {
+	// On an error or cancellation the blob being packed is never
+	// finalized, so its temp file must be removed here. After a
+	// successful flush there is no such blob and this does nothing.
+	defer s.packer.DiscardCurrentBlob()
+
 	// Calculate total bytes to process
 	var totalBytes int64
 	for _, f := range filesToProcess {

internal/snapshot/skip_errors_test.go

@@ -381,3 +381,60 @@ func TestScannerCancelStopsSkipErrorsRun(t *testing.T) {
 		})
 	}
 }
+
+// TestScannerRemovesBlobTempFileWhenRunStops checks that a run stopped
+// part-way, by a file it cannot read or by a cancellation, removes the
+// temp file of the blob it was packing.
+func TestScannerRemovesBlobTempFileWhenRunStops(t *testing.T) {
+	t.Parallel()
+
+	// a.txt is backed up first and starts a blob; the run stops at b.txt.
+	const target = "/source/b.txt"
+
+	tests := []struct {
+		name  string
+		newFs func(cancel context.CancelFunc) afero.Fs
+	}{
+		{
+			name: "file cannot be read",
+			newFs: func(context.CancelFunc) afero.Fs {
+				return &readFailFs{Fs: afero.NewMemMapFs(), target: target}
+			},
+		},
+		{
+			name: "cancelled",
+			newFs: func(cancel context.CancelFunc) afero.Fs {
+				return &cancelOnOpenFs{
+					Fs: afero.NewMemMapFs(), target: target, cancel: cancel,
+				}
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			ctx, cancel := context.WithCancel(context.Background())
+			defer cancel()
+
+			fs := tt.newFs(cancel)
+			writeSkipErrorTestFile(t, fs, "/source/a.txt", "first file content")
+			writeSkipErrorTestFile(t, fs, target, "second file content")
+
+			_, err := runSkipErrorScan(ctx, t, fs, "/source", false, nil)
+			if err == nil {
+				t.Fatal("expected the scan to stop with an error, got nil")
+			}
+
+			left, err := afero.Glob(fs, filepath.Join(os.TempDir(), "vaultik-blob-*"))
+			if err != nil {
+				t.Fatalf("listing blob temp files: %v", err)
+			}
+
+			if len(left) != 0 {
+				t.Fatalf("expected no blob temp file left, got %v", left)
+			}
+		})
+	}
+}

internal/storage/file.go

@@ -120,10 +120,9 @@ func (f *FileStorer) Delete(_ context.Context, key string) error {
 	return nil
 }
 
-// List returns all keys with the given prefix, reading through symlinked
+// List returns all keys with the given prefix. It fails when the
-// directories. It fails when the destination directory is missing or the
+// destination directory is missing; a missing prefix under it is an
-// prefix is a symlink whose target is missing; a missing prefix under the
+// empty listing.
-// destination directory is an empty listing.
 func (f *FileStorer) List(ctx context.Context, prefix string) ([]string, error) {
 	var keys []string
 
@@ -134,7 +133,8 @@ func (f *FileStorer) List(ctx context.Context, prefix string) ([]string, error)
 
 	basePath := f.fullPath(prefix)
 
-	exists, err := f.prefixExists(basePath)
+	// Check if the prefix exists
+	exists, err := afero.Exists(f.fs, basePath)
 	if err != nil {
 		return nil, fmt.Errorf("checking path: %w", err)
 	}
@@ -143,7 +143,7 @@ func (f *FileStorer) List(ctx context.Context, prefix string) ([]string, error)
 		return keys, nil // Empty list for non-existent prefix
 	}
 
-	err = f.walk(basePath, func(path string, info os.FileInfo, err error) error {
+	err = afero.Walk(f.fs, basePath, func(path string, info os.FileInfo, err error) error {
 		if err != nil {
 			return err
 		}
@@ -176,9 +176,7 @@ func (f *FileStorer) List(ctx context.Context, prefix string) ([]string, error)
 }
 
 // ListStream returns a channel of ObjectInfo for large result sets. Like
-// List, it reads through symlinked directories and sends an error when
+// List, it sends an error when the destination directory is missing.
-// the destination directory is missing or the prefix is a symlink whose
-// target is missing.
 func (f *FileStorer) ListStream(ctx context.Context, prefix string) <-chan ObjectInfo {
 	ch := make(chan ObjectInfo)
 
@@ -194,7 +192,8 @@ func (f *FileStorer) ListStream(ctx context.Context, prefix string) <-chan Objec
 
 		basePath := f.fullPath(prefix)
 
-		exists, err := f.prefixExists(basePath)
+		// Check if the prefix exists
+		exists, err := afero.Exists(f.fs, basePath)
 		if err != nil {
 			ch <- ObjectInfo{Err: fmt.Errorf("checking path: %w", err)}
 
@@ -205,7 +204,7 @@ func (f *FileStorer) ListStream(ctx context.Context, prefix string) <-chan Objec
 			return // Empty channel for non-existent prefix
 		}
 
-		_ = f.walk(basePath, func(path string, info os.FileInfo, err error) error {
+		_ = afero.Walk(f.fs, basePath, func(path string, info os.FileInfo, err error) error {
 			// Check context cancellation
 			select {
 			case <-ctx.Done():
@@ -353,40 +352,6 @@ func (f *FileStorer) writeAtomic(
 	return nil
 }
 
-// walk is afero.Walk, except that it reads through a symlinked directory
-// the way Get and Stat do, where afero.Walk reports the link as one file.
-// afero.Walk uses Lstat, which does not follow a link, whenever the
-// filesystem has one; the struct below carries only the afero.Fs methods,
-// so the walk uses Stat instead. A link back up the tree is followed until
-// the operating system refuses the path for too many levels of links, and
-// the walk then fails.
-func (f *FileStorer) walk(root string, fn filepath.WalkFunc) error {
-	return afero.Walk(struct{ afero.Fs }{f.fs}, root, fn)
-}
-
-// prefixExists is afero.Exists, except that it does not follow a symlink
-// at path. A symlinked prefix whose target is missing, such as a link to
-// a volume that is not mounted, therefore exists, and walk then fails on
-// it; with afero.Exists it would list as empty, and prune would delete
-// every blob.
-func (f *FileStorer) prefixExists(path string) (bool, error) {
-	lstater, ok := f.fs.(afero.Lstater)
-	if !ok {
-		return afero.Exists(f.fs, path)
-	}
-
-	_, _, err := lstater.LstatIfPossible(path)
-	if err == nil {
-		return true, nil
-	}
-
-	if os.IsNotExist(err) {
-		return false, nil
-	}
-
-	return false, err
-}
-
 // fullPath returns the full filesystem path for a key.
 func (f *FileStorer) fullPath(key string) string {
 	return filepath.Join(f.basePath, key)

internal/storage/file_backend_test.go

@@ -4,10 +4,7 @@ import (
 	"context"
 	"errors"
 	"io/fs"
-	"os"
 	"path/filepath"
-	"reflect"
-	"strings"
 	"testing"
 
 	"sneak.berlin/go/vaultik/internal/storage"
@@ -63,151 +60,3 @@ func TestFileStorerListMissingDestination(t *testing.T) {
 		t.Errorf("ListStream error = %v, want a not-exist error", streamErr)
 	}
 }
-
-// TestFileStorerListsThroughSymlinkedDirectory checks that List and
-// ListStream read through a symlinked metadata/ or blobs/ directory, as Get
-// and Stat do, instead of listing the link as one key. Listing the whole
-// destination meets the link part-way through the walk; listing its prefix
-// starts the walk at the link.
-func TestFileStorerListsThroughSymlinkedDirectory(t *testing.T) {
-	t.Parallel()
-
-	for _, dir := range []string{"metadata", "blobs"} {
-		t.Run(dir, func(t *testing.T) {
-			t.Parallel()
-
-			base := t.TempDir()
-			key := dir + "/aa/bb/object"
-
-			s, err := storage.NewFileStorer(base)
-			if err != nil {
-				t.Fatalf("NewFileStorer: %v", err)
-			}
-
-			err = s.Put(context.Background(), key, strings.NewReader("data"))
-			if err != nil {
-				t.Fatalf("Put: %v", err)
-			}
-
-			linkPath := filepath.Join(base, dir)
-			movedPath := filepath.Join(t.TempDir(), dir)
-
-			err = os.Rename(linkPath, movedPath)
-			if err != nil {
-				t.Fatalf("moving %s away: %v", dir, err)
-			}
-
-			err = os.Symlink(movedPath, linkPath)
-			if err != nil {
-				t.Fatalf("linking %s: %v", dir, err)
-			}
-
-			want := []string{key}
-
-			for _, prefix := range []string{"", dir + "/"} {
-				got := listSorted(t, s, prefix)
-				if !reflect.DeepEqual(got, want) {
-					t.Errorf("List(%q) = %v, want %v", prefix, got, want)
-				}
-
-				got = listStreamKeys(t, s, prefix)
-				if !reflect.DeepEqual(got, want) {
-					t.Errorf("ListStream(%q) = %v, want %v", prefix, got, want)
-				}
-			}
-		})
-	}
-}
-
-// TestFileStorerListFailsOnSymlinkWithMissingTarget checks that List and
-// ListStream fail on a symlinked metadata/ or blobs/ directory whose target
-// is missing, such as a link to a volume that is not mounted, as they do on
-// a missing destination directory, instead of listing it as empty.
-func TestFileStorerListFailsOnSymlinkWithMissingTarget(t *testing.T) {
-	t.Parallel()
-
-	ctx := context.Background()
-
-	for _, dir := range []string{"metadata", "blobs"} {
-		t.Run(dir, func(t *testing.T) {
-			t.Parallel()
-
-			base := t.TempDir()
-
-			s, err := storage.NewFileStorer(base)
-			if err != nil {
-				t.Fatalf("NewFileStorer: %v", err)
-			}
-
-			unmounted := filepath.Join(t.TempDir(), "unmounted")
-
-			err = os.Symlink(unmounted, filepath.Join(base, dir))
-			if err != nil {
-				t.Fatalf("Symlink: %v", err)
-			}
-
-			for _, prefix := range []string{"", dir + "/"} {
-				keys, err := s.List(ctx, prefix)
-				if !errors.Is(err, fs.ErrNotExist) {
-					t.Errorf("List(%q) = %v, %v; want a not-exist error",
-						prefix, keys, err)
-				}
-
-				var streamErr error
-
-				for object := range s.ListStream(ctx, prefix) {
-					if object.Err != nil {
-						streamErr = object.Err
-					}
-				}
-
-				if !errors.Is(streamErr, fs.ErrNotExist) {
-					t.Errorf("ListStream(%q) error = %v, want a not-exist error",
-						prefix, streamErr)
-				}
-			}
-		})
-	}
-}
-
-// TestFileStorerListFailsOnSymlinkLoop checks that a symlink pointing back
-// at the destination makes List and ListStream fail instead of walking it
-// forever.
-func TestFileStorerListFailsOnSymlinkLoop(t *testing.T) {
-	t.Parallel()
-
-	ctx := context.Background()
-	base := t.TempDir()
-
-	s, err := storage.NewFileStorer(base)
-	if err != nil {
-		t.Fatalf("NewFileStorer: %v", err)
-	}
-
-	err = s.Put(ctx, testBlobKey, strings.NewReader("data"))
-	if err != nil {
-		t.Fatalf("Put: %v", err)
-	}
-
-	err = os.Symlink(base, filepath.Join(base, "blobs", "loop"))
-	if err != nil {
-		t.Fatalf("Symlink: %v", err)
-	}
-
-	keys, err := s.List(ctx, "blobs/")
-	if err == nil {
-		t.Errorf("List = %d keys and no error, want an error", len(keys))
-	}
-
-	var streamErr error
-
-	for object := range s.ListStream(ctx, "blobs/") {
-		if object.Err != nil {
-			streamErr = object.Err
-		}
-	}
-
-	if streamErr == nil {
-		t.Error("ListStream sent no error, want one")
-	}
-}

internal/vaultik/snapshot.go

@@ -28,8 +28,14 @@ var (
 	errNoAgeRecipients      = errors.New(
 		"creating a snapshot needs at least one public key in " +
 			"age_recipients (generate a keypair with: age-keygen)")
+	errKeepNewerThanNeedsPrune = errors.New("--keep-newer-than requires --prune")
 )
 
+// ErrPostBackupPruneFailed wraps a failure of the post-backup prune,
+// which runs only after every snapshot was created and uploaded, so the
+// caller can report it apart from a failed backup.
+var ErrPostBackupPruneFailed = errors.New("post-backup prune failed")
+
 // listRecentLimit caps how many snapshot rows are fetched from the
 // local index for listing and purge operations.
 const listRecentLimit = 10000
@@ -45,6 +51,26 @@ type SnapshotCreateOptions struct {
 	Snapshots     []string // Optional list of snapshot names to process (empty = all)
 }
 
+// Validate fails when KeepNewerThan is set without Prune or is not a
+// valid duration. Only the post-backup prune reads KeepNewerThan, after
+// the backup, so the caller checks it before starting one.
+func (opts *SnapshotCreateOptions) Validate() error {
+	if opts.KeepNewerThan == "" {
+		return nil
+	}
+
+	if !opts.Prune {
+		return errKeepNewerThanNeedsPrune
+	}
+
+	_, err := parseDuration(opts.KeepNewerThan)
+	if err != nil {
+		return fmt.Errorf("--keep-newer-than: %w", err)
+	}
+
+	return nil
+}
+
 // CreateSnapshot executes the snapshot creation operation
 func (v *Vaultik) CreateSnapshot(opts *SnapshotCreateOptions) error {
 	// config.Load accepts an empty list, since listing, verifying and
@@ -123,7 +149,7 @@ func (v *Vaultik) CreateSnapshot(opts *SnapshotCreateOptions) error {
 	if opts.Prune {
 		err = v.runPostBackupPrune(snapshotNames, opts.KeepNewerThan)
 		if err != nil {
-			return fmt.Errorf("post-backup prune: %w", err)
+			return fmt.Errorf("%w: %w", ErrPostBackupPruneFailed, err)
 		}
 	}
 

internal/vaultik/symlinked_destination_test.go

@@ -1,121 +0,0 @@
-package vaultik_test
-
-import (
-	"context"
-	"io/fs"
-	"os"
-	"path/filepath"
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-	"sneak.berlin/go/vaultik/internal/log"
-	"sneak.berlin/go/vaultik/internal/vaultik"
-)
-
-// TestPruneDeletesNothingThroughSymlinkedDirectory checks that prune keeps
-// every blob and the local snapshot record when the metadata/ or blobs/
-// directory of a file:// destination is a symlink to a directory elsewhere
-// (https://git.eeqj.de/sneak/vaultik/issues/296). A backup writes through
-// such a link, so prune has to list through it too.
-func TestPruneDeletesNothingThroughSymlinkedDirectory(t *testing.T) {
-	log.Initialize(log.Config{})
-	t.Parallel()
-
-	for _, dir := range []string{"metadata", "blobs"} {
-		t.Run(dir, func(t *testing.T) {
-			t.Parallel()
-
-			ctx := context.Background()
-			storeDir := filepath.Join(t.TempDir(), "store")
-			v, repos, _ := backUpToFileDestination(ctx, t, storeDir)
-			blobFiles := blobFilesIn(t, storeDir)
-			moveBehindSymlink(t, storeDir, dir)
-
-			require.NoError(t, v.Prune(&vaultik.PruneOptions{Force: true}))
-
-			// When blobs/ is the link, these paths run through it.
-			for _, blobFile := range blobFiles {
-				assert.FileExists(t, blobFile, "prune must delete no blob")
-			}
-
-			snapshots, err := repos.Snapshots.ListRecent(ctx, listRecentTestLimit)
-			require.NoError(t, err)
-			assert.Len(t, snapshots, 1, "prune must delete no local snapshot record")
-		})
-	}
-}
-
-// TestPruneFailsOnSymlinkedDirectoryWithMissingTarget checks that prune
-// fails, deleting no blob and keeping the local snapshot record, when the
-// metadata/ or blobs/ directory of a file:// destination is a symlink
-// whose target is missing, as a link to a volume that is not mounted is.
-func TestPruneFailsOnSymlinkedDirectoryWithMissingTarget(t *testing.T) {
-	log.Initialize(log.Config{})
-	t.Parallel()
-
-	for _, dir := range []string{"metadata", "blobs"} {
-		t.Run(dir, func(t *testing.T) {
-			t.Parallel()
-
-			ctx := context.Background()
-			storeDir := filepath.Join(t.TempDir(), "store")
-			v, repos, _ := backUpToFileDestination(ctx, t, storeDir)
-			blobFiles := blobFilesIn(t, storeDir)
-			targetPath := moveBehindSymlink(t, storeDir, dir)
-
-			// Unmount the volume the link points to, and mount it again
-			// once prune has run.
-			unmountedPath := targetPath + "-unmounted"
-			require.NoError(t, os.Rename(targetPath, unmountedPath))
-
-			err := v.Prune(&vaultik.PruneOptions{Force: true})
-			require.ErrorIs(t, err, fs.ErrNotExist)
-
-			require.NoError(t, os.Rename(unmountedPath, targetPath))
-
-			// When blobs/ is the link, these paths run through it.
-			for _, blobFile := range blobFiles {
-				assert.FileExists(t, blobFile, "prune must delete no blob")
-			}
-
-			snapshots, err := repos.Snapshots.ListRecent(ctx, listRecentTestLimit)
-			require.NoError(t, err)
-			assert.Len(t, snapshots, 1, "prune must delete no local snapshot record")
-		})
-	}
-}
-
-// blobFilesIn returns the paths of the blob files under storeDir/blobs, and
-// fails the test when there are none.
-func blobFilesIn(t *testing.T, storeDir string) []string {
-	t.Helper()
-
-	var blobFiles []string
-
-	err := filepath.WalkDir(filepath.Join(storeDir, "blobs"),
-		func(path string, entry fs.DirEntry, err error) error {
-			if err == nil && !entry.IsDir() {
-				blobFiles = append(blobFiles, path)
-			}
-
-			return err
-		})
-	require.NoError(t, err)
-	require.NotEmpty(t, blobFiles)
-
-	return blobFiles
-}
-
-// moveBehindSymlink moves storeDir/dir to a directory elsewhere, puts a
-// symlink to it in its place, and returns where it went.
-func moveBehindSymlink(t *testing.T, storeDir, dir string) string {
-	t.Helper()
-
-	linkPath := filepath.Join(storeDir, dir)
-	targetPath := filepath.Join(t.TempDir(), dir)
-	require.NoError(t, os.Rename(linkPath, targetPath))
-	require.NoError(t, os.Symlink(targetPath, linkPath))
-
-	return targetPath
-}