Skip removed paths silently and fix the progress line (closes #133)

A path removed while the scan runs gets no warning and no skipped
count, in the walk or the hash phase. If the first of several hard
links is gone, the next is read. Other errors are still warned about.

On a terminal every display is the library's spinner, then the line. A
phase with an exact total ends the padded line with its percent and a
bar at a fixed column, drawn by sfdupes, as the library shows no
spinner beside its own bar. A too-wide line loses its rate first.

The time remaining is labelled remain, not eta.

Judgement call: an operand removed mid-scan is skipped silently too.
Deviation: README's stalled-line example keeps its words on 100
columns, not 80.

Model: opus-5-5

TODO.md

@@ -29,19 +29,6 @@
 
 # Completed Steps
 
-- `README.md` rewritten from scratch, sentence by sentence, as a newcomer reads
-  it. It leads with what the program is and how to use it. A reference section
-  covers every setting and every subcommand. Development and testing come last.
-  Every statement was checked against the code on `next`. Five comments in
-  `main_test.go` cite "Settings", where their rules now live. One comment each
-  in `scan_test.go`, `trees_test.go` and `exclude_test.go` cites what the README
-  now says (2026-10-26, https://git.eeqj.de/sneak/sfdupes/issues/135)
-
-- an operand at or inside a directory named `.zfs` is never scanned, whether
-  given alone or under another operand. `scan` warns about it, counts it as
-  skipped and does not walk it (2026-10-26,
-  https://git.eeqj.de/sneak/sfdupes/issues/142)
-
 - a file or directory removed while the scan runs is not an error, in the walk
   or in the hash phase. The scan prints no line for it and does not count it as
   skipped. When the first of several hard links to a file is gone, the hash

exclude_test.go

@@ -17,9 +17,7 @@ import (
 func TestDefaultExcludes(t *testing.T) {
 	t.Parallel()
 
-	// README "Rules for the walk": the Linux and macOS lists, and none
-	// on any other system. The Windows list exists in the code only: the
-	// binary does not build for Windows, so the README leaves it out.
+	// README "Rules for the walk": each system's list.
 	cases := map[string][]string{
 		goosLinux: {"/proc", "/sys", "/dev", "/run", "/tmp", "/var/tmp"},
 		goosDarwin: {

main_test.go

@@ -393,7 +393,7 @@ func TestRunNamesRelativeDatabase(t *testing.T) {
 }
 
 func TestRunUsesDatabaseThroughSymlinkedDirectory(t *testing.T) {
-	// README §Settings: the path names the file exactly. With link a
+	// README §Database: the path names the file exactly. With link a
 	// symlink to the directory real/sub, link/../db.sqlite names
 	// real/db.sqlite, not db.sqlite beside link. Every subcommand must
 	// use that file, relative or absolute, and its first line must name
@@ -648,7 +648,7 @@ func TestRunUsageErrors(t *testing.T) {
 }
 
 func TestRunScanRejectsWorkersBelowOne(t *testing.T) {
-	// README §Settings: --workers below 1 is a usage error reported in
+	// README §scan mode: --workers below 1 is a usage error reported in
 	// one line on stderr, before the scan opens the database.
 	for _, workers := range []string{"0", "-1"} {
 		t.Run(workers, func(t *testing.T) {
@@ -686,8 +686,8 @@ func TestRunScanRejectsWorkersBelowOne(t *testing.T) {
 func TestRunHelp(t *testing.T) {
 	t.Parallel()
 
-	// README §Settings: help goes to stderr, exits 0, and leaves stdout
-	// empty.
+	// README §Subcommands: help goes to stderr, exits 0, and leaves
+	// stdout empty.
 	cases := [][]string{{"--help"}, {"-h"}, {cmdScan, "--help"}}
 
 	for _, args := range cases {
@@ -713,8 +713,8 @@ func TestRunHelp(t *testing.T) {
 func TestRunVersion(t *testing.T) {
 	t.Parallel()
 
-	// README §Settings: the version is one line on stdout, with nothing
-	// on stderr, and exits 0.
+	// README §Subcommands: the version is one line on stdout, with
+	// nothing on stderr, and exits 0.
 	info, _ := debug.ReadBuildInfo()
 
 	for _, arg := range []string{"--version", "-v"} {
@@ -773,8 +773,8 @@ func TestBuildVersion(t *testing.T) {
 func TestRunVersionWriteFailureIsFatal(t *testing.T) {
 	t.Parallel()
 
-	// README §Error handling: a failed write to stdout is a fatal error,
-	// exit 1, reported on stderr starting with "sfdupes:".
+	// README §Error handling: a stdout write failure exits 1, reported
+	// in one line on stderr.
 	var stderr bytes.Buffer
 
 	code := run([]string{"--version"}, failingWriter{}, &stderr)
@@ -928,21 +928,24 @@ func TestRunScanWalksOperandUnderSymlinkOperand(t *testing.T) {
 }
 
 func TestRunScanSkipsZFSOperand(t *testing.T) {
-	zfs := filepath.Join(t.TempDir(), ".zfs")
-	f := writeFile(t, zfs, "snapshot/hourly/f", pattern(1, 10))
-
-	// No scan records a file inside a .zfs directory, so the record
-	// beneath the operand is written straight into the database.
-	path := seedDatabase(t, []scanRec{{size: 10, path: f}})
+	path := testDBPath(t)
 	t.Setenv(databaseEnv, path)
 
+	zfs := filepath.Join(t.TempDir(), ".zfs")
+	snapshot := filepath.Join(zfs, "snapshot", "hourly")
+	f := writeFile(t, snapshot, "f", pattern(1, 10))
+
+	// An operand beneath a .zfs directory is walked, because it is not
+	// itself named .zfs.
+	scanOK(t, snapshot)
+
 	assertOperandSkipped(t, path, zfs, ".zfs directory", f)
 }
 
 // assertOperandSkipped scans operand alone and checks that it is skipped
 // as kind: a warning naming it, one skip in the summary, exit 0, and the
-// record for kept, stored beneath operand before this scan, still in the
-// database at dbPath.
+// record for kept, which an earlier scan stored beneath operand, still
+// in the database at dbPath.
 func assertOperandSkipped(t *testing.T, dbPath, operand, kind,
 	kept string,
 ) {
@@ -971,121 +974,6 @@ func assertOperandSkipped(t *testing.T, dbPath, operand, kind,
 	recordByPath(t, dbRecords(t, db), kept)
 }
 
-// TestRunScanSkipsOperandInsideZFS scans a directory inside a .zfs
-// directory, first alone and then under another operand. Each time it
-// is warned about and counted as skipped, and nothing in it is walked.
-// The other operand is scanned as usual.
-func TestRunScanSkipsOperandInsideZFS(t *testing.T) {
-	path := testDBPath(t)
-	t.Setenv(databaseEnv, path)
-
-	dir := t.TempDir()
-	hourly := filepath.Join(dir, ".zfs", "snapshot", "hourly")
-	writeFile(t, hourly, "f", pattern(1, 10))
-	f := writeFile(t, dir, "f", pattern(2, 10))
-
-	warning := "walk " + hourly + ": skipping operand inside a .zfs directory\n"
-
-	for _, tc := range []struct {
-		operands []string
-		summary  string
-	}{
-		{
-			[]string{hourly},
-			"scan: 0 files seen (0 added, 0 updated, 0 removed, " +
-				"0 unchanged), 1 skipped\n",
-		},
-		{
-			[]string{dir, hourly},
-			"scan: 1 files seen (1 added, 0 updated, 0 removed, " +
-				"0 unchanged), 1 skipped\n",
-		},
-	} {
-		stderr := scanOK(t, tc.operands...)
-		if !strings.Contains(stderr, warning) ||
-			!strings.Contains(stderr, tc.summary) {
-			t.Errorf("scan %q: stderr = %q, want %q and %q", tc.operands,
-				stderr, warning, tc.summary)
-		}
-	}
-
-	db, err := openDB(path, reportParams)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	t.Cleanup(func() { _ = db.Close() })
-
-	if got := recordPaths(dbRecords(t, db)); !slices.Equal(got, []string{f}) {
-		t.Errorf("records = %q, want %q", got, []string{f})
-	}
-}
-
-// TestRunScanSkipsOperandThroughSymlinkIntoZFS scans snaps/daily, where
-// snaps is a symlink to pool/.zfs/snapshot. The operand is warned about
-// by the path given, counted as skipped, and not walked.
-func TestRunScanSkipsOperandThroughSymlinkIntoZFS(t *testing.T) {
-	t.Setenv(databaseEnv, testDBPath(t))
-
-	dir := t.TempDir()
-	writeFile(t, dir, "pool/.zfs/snapshot/daily/f", pattern(1, 10))
-
-	snaps := filepath.Join(dir, "snaps")
-
-	err := os.Symlink(filepath.Join(dir, "pool", ".zfs", "snapshot"), snaps)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	daily := filepath.Join(snaps, "daily")
-	stderr := scanOK(t, daily)
-
-	warning := "walk " + daily + ": skipping operand inside a .zfs directory\n"
-	summary := "scan: 0 files seen (0 added, 0 updated, 0 removed, " +
-		"0 unchanged), 1 skipped\n"
-
-	if !strings.Contains(stderr, warning) ||
-		!strings.Contains(stderr, summary) {
-		t.Errorf("stderr = %q, want %q and %q", stderr, warning, summary)
-	}
-}
-
-// TestRunScanWalksOperandThroughSymlink scans data/daily, where data is
-// a symlink to a directory outside any .zfs directory. The operand is
-// scanned as usual, and its file is recorded by the path given.
-func TestRunScanWalksOperandThroughSymlink(t *testing.T) {
-	path := testDBPath(t)
-	t.Setenv(databaseEnv, path)
-
-	dir := t.TempDir()
-	writeFile(t, dir, "pool/data/daily/f", pattern(1, 10))
-
-	data := filepath.Join(dir, "data")
-
-	err := os.Symlink(filepath.Join(dir, "pool", "data"), data)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	daily := filepath.Join(data, "daily")
-	stderr := scanOK(t, daily)
-
-	summary := "scan: 1 files seen (1 added, 0 updated, 0 removed, " +
-		"0 unchanged), 0 skipped\n"
-	if !strings.Contains(stderr, summary) {
-		t.Errorf("stderr = %q, want %q", stderr, summary)
-	}
-
-	db, err := openDB(path, reportParams)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	t.Cleanup(func() { _ = db.Close() })
-
-	recordByPath(t, dbRecords(t, db), filepath.Join(daily, "f"))
-}
-
 func TestRunReportSucceeds(t *testing.T) {
 	path := testDBPath(t)
 	t.Setenv(databaseEnv, path)
@@ -1234,7 +1122,7 @@ func assertRunsUseDatabase(t *testing.T, dir, name string) {
 }
 
 func TestRunDatabasePathUsedAsGiven(t *testing.T) {
-	// README §Settings: the path names the database file exactly. In
+	// README §Database: the path names the database file exactly. In
 	// SQLite's connection string an unescaped ? or # would end the file
 	// name and % would start an escape, and a path starting with //
 	// could be read as a host name. %25 is a valid escape, so unescaped
@@ -1279,8 +1167,9 @@ func holdScanLock(t *testing.T, path string) {
 }
 
 func TestRunSecondScanFails(t *testing.T) {
-	// README §Database: a second scan that finds the lock held fails
-	// at once, naming the lock file, without opening the database.
+	// README §Database: while one scan holds the lock, a second scan
+	// fails at once, naming the lock file, without opening the
+	// database.
 	path := testDBPath(t)
 	t.Setenv(databaseEnv, path)
 
@@ -1339,7 +1228,7 @@ func assertSecondScanFails(t *testing.T, path string) {
 }
 
 func TestRunSecondScanThroughSymlinkFails(t *testing.T) {
-	// README §Database: a path through a symlink names the same lock
+	// README §Database: every path to one database names the same lock
 	// file, so while a scan holds it through one path, a scan through
 	// another fails, naming the lock file beside the database's real
 	// path.
@@ -1444,8 +1333,8 @@ func TestRunReportsDuringScan(t *testing.T) {
 }
 
 func TestRunStdoutClosedIsFatal(t *testing.T) {
-	// README §Error handling: a failed write to stdout is a fatal error,
-	// exit 1, reported on stderr starting with "sfdupes:".
+	// README §Error handling: a stdout write failure exits 1, reported
+	// in one line on stderr.
 	for _, name := range []string{cmdReport, cmdTrees, cmdInfo} {
 		t.Run(name, func(t *testing.T) {
 			t.Setenv(databaseEnv, testDBPath(t))

scan.go

@@ -383,8 +383,7 @@ func (s *scanState) runPhases(ctx context.Context, roots []string,
 ) error {
 	// Types and filesystems are checked before pruning so that an
 	// operand under a dropped one is still scanned, not dropped as lying
-	// under it, and so that an operand inside a .zfs directory gets its
-	// warning even when it lies under another operand.
+	// under it.
 	roots = pruneRoots(s.walkableRoots(roots, rules), oneFS, rules,
 		deviceOfPath)
 
@@ -412,15 +411,15 @@ func (s *scanState) runPhases(ctx context.Context, roots []string,
 }
 
 // walkableRoots returns the operands the walk can start from: regular
-// files, and directories not named .zfs, none of them inside a
-// directory named .zfs. Every other operand is warned about, counted as
-// skipped, and dropped. A dropped operand is no longer a root, so the
-// records stored beneath it are treated as if it had not been given:
-// those under no other root count as outside the roots and are not
-// deleted as unverified. An operand on a filesystem in rules that is not
-// persistent is dropped the same way, with a line saying so that is not
-// a warning, and is not counted as skipped. An operand that fails lstat
-// here is kept, and the walk warns about it unless it no longer exists.
+// files, and directories not named .zfs. Every other operand is warned
+// about, counted as skipped, and dropped. A dropped operand is no
+// longer a root, so the records stored beneath it are treated as if it
+// had not been given: those under no other root count as outside the
+// roots and are not deleted as unverified. An operand on a filesystem
+// in rules that is not persistent is dropped the same way, with a line
+// saying so that is not a warning, and is not counted as skipped. An
+// operand that fails lstat here is kept, and the walk warns about it
+// unless it no longer exists.
 func (s *scanState) walkableRoots(roots []string, rules walkRules) []string {
 	kept := make([]string, 0, len(roots))
 
@@ -875,24 +874,9 @@ func sendEvent(ctx context.Context, events chan<- walkEvent,
 
 // operandWarning returns the one-line warning for an operand the walk
 // does not start from, naming the path and what it is, or "" for one it
-// does: a regular file, or a directory not named .zfs, that is not
-// inside a directory named .zfs, neither as given nor with its symlinks
-// resolved. Symlinks are never followed, including as operands.
+// does: a regular file, or a directory not named .zfs. Symlinks are
+// never followed, including as operands.
 func operandWarning(root string, fi fs.FileInfo) string {
-	// The walk never enters a .zfs directory, so it starts from nothing
-	// inside one either, not even through a symlink. An operand whose
-	// symlinks cannot be resolved is checked as given.
-	resolved, err := filepath.EvalSymlinks(root)
-	if err != nil {
-		resolved = root
-	}
-
-	if slices.Contains(strings.Split(filepath.Dir(root), "/"), ".zfs") ||
-		slices.Contains(strings.Split(filepath.Dir(resolved), "/"), ".zfs") {
-		return fmt.Sprintf("walk %s: skipping operand inside a .zfs directory",
-			root)
-	}
-
 	var kind string
 
 	switch mode := fi.Mode(); {

scan_test.go

@@ -1064,9 +1064,8 @@ func TestScanOneFilesystemWalksNestedFileOperand(t *testing.T) {
 	}
 }
 
-// buildSmokeTree recreates the tree of the test under README
-// "Definition of done" with deterministic content and returns the tree
-// root.
+// buildSmokeTree recreates the README smoke-test filesystem layout
+// with deterministic content and returns the tree root.
 func buildSmokeTree(t *testing.T) string {
 	t.Helper()
 

trees_test.go

@@ -15,9 +15,8 @@ import (
 const treesOpenLine = "[1/4] open: opening the database, elapsed 0s, " +
 	"remain unknown"
 
-// smokeTreeRecs mirrors the tree of the test under README "Definition
-// of done": /d/t1 and /d/t2 are identical, /d/t3 differs from them only
-// by one filename.
+// smokeTreeRecs mirrors the README smoke-test tree layout: /d/t1 and
+// /d/t2 are identical, /d/t3 differs from them only by one filename.
 func smokeTreeRecs() []scanRec {
 	f1Head, f1Tail, f1Content := testHash("f1h"), testHash("f1t"), testHash("f1c")
 	f2Head, f2Tail, f2Content := testHash("f2h"), testHash("f2t"), testHash("f2c")