Add file exclusion support (sgard exclude/include).

Paths added to the manifest's exclude list are skipped during Add,
MirrorUp, and MirrorDown directory walks. Excluding a directory
excludes everything under it. Already-tracked entries matching a
new exclusion are removed from the manifest.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

garden/exclude.go

@@ -0,0 +1,80 @@
+package garden
+
+import (
+	"fmt"
+	"path/filepath"
+)
+
+// Exclude adds the given paths to the manifest's exclusion list. Excluded
+// paths are skipped during Add and MirrorUp directory walks. If any of the
+// paths are already tracked, they are removed from the manifest.
+func (g *Garden) Exclude(paths []string) error {
+	existing := make(map[string]bool, len(g.manifest.Exclude))
+	for _, e := range g.manifest.Exclude {
+		existing[e] = true
+	}
+
+	for _, p := range paths {
+		abs, err := filepath.Abs(p)
+		if err != nil {
+			return fmt.Errorf("resolving path %s: %w", p, err)
+		}
+
+		tilded := toTildePath(abs)
+
+		if existing[tilded] {
+			continue
+		}
+
+		g.manifest.Exclude = append(g.manifest.Exclude, tilded)
+		existing[tilded] = true
+
+		// Remove any already-tracked entries that match this exclusion.
+		g.removeExcludedEntries(tilded)
+	}
+
+	if err := g.manifest.Save(g.manifestPath); err != nil {
+		return fmt.Errorf("saving manifest: %w", err)
+	}
+
+	return nil
+}
+
+// Include removes the given paths from the manifest's exclusion list,
+// allowing them to be tracked again.
+func (g *Garden) Include(paths []string) error {
+	remove := make(map[string]bool, len(paths))
+	for _, p := range paths {
+		abs, err := filepath.Abs(p)
+		if err != nil {
+			return fmt.Errorf("resolving path %s: %w", p, err)
+		}
+		remove[toTildePath(abs)] = true
+	}
+
+	filtered := g.manifest.Exclude[:0]
+	for _, e := range g.manifest.Exclude {
+		if !remove[e] {
+			filtered = append(filtered, e)
+		}
+	}
+	g.manifest.Exclude = filtered
+
+	if err := g.manifest.Save(g.manifestPath); err != nil {
+		return fmt.Errorf("saving manifest: %w", err)
+	}
+
+	return nil
+}
+
+// removeExcludedEntries drops manifest entries that match the given
+// exclusion path (exact match or under an excluded directory).
+func (g *Garden) removeExcludedEntries(tildePath string) {
+	kept := g.manifest.Files[:0]
+	for _, e := range g.manifest.Files {
+		if !g.manifest.IsExcluded(e.Path) {
+			kept = append(kept, e)
+		}
+	}
+	g.manifest.Files = kept
+}

garden/exclude_test.go

@@ -0,0 +1,331 @@
+package garden
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestExcludeAddsToManifest(t *testing.T) {
+	root := t.TempDir()
+	repoDir := filepath.Join(root, "repo")
+
+	g, err := Init(repoDir)
+	if err != nil {
+		t.Fatalf("Init: %v", err)
+	}
+
+	secretFile := filepath.Join(root, "secret.key")
+	if err := os.WriteFile(secretFile, []byte("secret"), 0o600); err != nil {
+		t.Fatalf("writing secret: %v", err)
+	}
+
+	if err := g.Exclude([]string{secretFile}); err != nil {
+		t.Fatalf("Exclude: %v", err)
+	}
+
+	if len(g.manifest.Exclude) != 1 {
+		t.Fatalf("expected 1 exclusion, got %d", len(g.manifest.Exclude))
+	}
+
+	expected := toTildePath(secretFile)
+	if g.manifest.Exclude[0] != expected {
+		t.Errorf("exclude[0] = %q, want %q", g.manifest.Exclude[0], expected)
+	}
+
+	// Verify persistence.
+	g2, err := Open(repoDir)
+	if err != nil {
+		t.Fatalf("re-Open: %v", err)
+	}
+	if len(g2.manifest.Exclude) != 1 {
+		t.Errorf("persisted excludes = %d, want 1", len(g2.manifest.Exclude))
+	}
+}
+
+func TestExcludeDeduplicates(t *testing.T) {
+	root := t.TempDir()
+	repoDir := filepath.Join(root, "repo")
+
+	g, err := Init(repoDir)
+	if err != nil {
+		t.Fatalf("Init: %v", err)
+	}
+
+	secretFile := filepath.Join(root, "secret.key")
+	if err := os.WriteFile(secretFile, []byte("secret"), 0o600); err != nil {
+		t.Fatalf("writing secret: %v", err)
+	}
+
+	if err := g.Exclude([]string{secretFile}); err != nil {
+		t.Fatalf("first Exclude: %v", err)
+	}
+	if err := g.Exclude([]string{secretFile}); err != nil {
+		t.Fatalf("second Exclude: %v", err)
+	}
+
+	if len(g.manifest.Exclude) != 1 {
+		t.Errorf("expected 1 exclusion after dedup, got %d", len(g.manifest.Exclude))
+	}
+}
+
+func TestExcludeRemovesTrackedEntry(t *testing.T) {
+	root := t.TempDir()
+	repoDir := filepath.Join(root, "repo")
+
+	g, err := Init(repoDir)
+	if err != nil {
+		t.Fatalf("Init: %v", err)
+	}
+
+	secretFile := filepath.Join(root, "secret.key")
+	if err := os.WriteFile(secretFile, []byte("secret"), 0o600); err != nil {
+		t.Fatalf("writing secret: %v", err)
+	}
+
+	// Add the file first.
+	if err := g.Add([]string{secretFile}); err != nil {
+		t.Fatalf("Add: %v", err)
+	}
+	if len(g.manifest.Files) != 1 {
+		t.Fatalf("expected 1 file, got %d", len(g.manifest.Files))
+	}
+
+	// Now exclude it — should remove from tracked files.
+	if err := g.Exclude([]string{secretFile}); err != nil {
+		t.Fatalf("Exclude: %v", err)
+	}
+
+	if len(g.manifest.Files) != 0 {
+		t.Errorf("expected 0 files after exclude, got %d", len(g.manifest.Files))
+	}
+}
+
+func TestIncludeRemovesFromExcludeList(t *testing.T) {
+	root := t.TempDir()
+	repoDir := filepath.Join(root, "repo")
+
+	g, err := Init(repoDir)
+	if err != nil {
+		t.Fatalf("Init: %v", err)
+	}
+
+	secretFile := filepath.Join(root, "secret.key")
+	if err := os.WriteFile(secretFile, []byte("secret"), 0o600); err != nil {
+		t.Fatalf("writing secret: %v", err)
+	}
+
+	if err := g.Exclude([]string{secretFile}); err != nil {
+		t.Fatalf("Exclude: %v", err)
+	}
+	if len(g.manifest.Exclude) != 1 {
+		t.Fatalf("expected 1 exclusion, got %d", len(g.manifest.Exclude))
+	}
+
+	if err := g.Include([]string{secretFile}); err != nil {
+		t.Fatalf("Include: %v", err)
+	}
+	if len(g.manifest.Exclude) != 0 {
+		t.Errorf("expected 0 exclusions after include, got %d", len(g.manifest.Exclude))
+	}
+}
+
+func TestAddSkipsExcludedFile(t *testing.T) {
+	root := t.TempDir()
+	repoDir := filepath.Join(root, "repo")
+
+	g, err := Init(repoDir)
+	if err != nil {
+		t.Fatalf("Init: %v", err)
+	}
+
+	testDir := filepath.Join(root, "config")
+	if err := os.MkdirAll(testDir, 0o755); err != nil {
+		t.Fatalf("creating dir: %v", err)
+	}
+
+	normalFile := filepath.Join(testDir, "settings.yaml")
+	secretFile := filepath.Join(testDir, "credentials.key")
+	if err := os.WriteFile(normalFile, []byte("settings"), 0o644); err != nil {
+		t.Fatalf("writing normal file: %v", err)
+	}
+	if err := os.WriteFile(secretFile, []byte("secret"), 0o600); err != nil {
+		t.Fatalf("writing secret file: %v", err)
+	}
+
+	// Exclude the secret file before adding the directory.
+	if err := g.Exclude([]string{secretFile}); err != nil {
+		t.Fatalf("Exclude: %v", err)
+	}
+
+	if err := g.Add([]string{testDir}); err != nil {
+		t.Fatalf("Add: %v", err)
+	}
+
+	if len(g.manifest.Files) != 1 {
+		t.Fatalf("expected 1 file, got %d", len(g.manifest.Files))
+	}
+
+	expectedPath := toTildePath(normalFile)
+	if g.manifest.Files[0].Path != expectedPath {
+		t.Errorf("tracked file = %q, want %q", g.manifest.Files[0].Path, expectedPath)
+	}
+}
+
+func TestAddSkipsExcludedDirectory(t *testing.T) {
+	root := t.TempDir()
+	repoDir := filepath.Join(root, "repo")
+
+	g, err := Init(repoDir)
+	if err != nil {
+		t.Fatalf("Init: %v", err)
+	}
+
+	testDir := filepath.Join(root, "config")
+	subDir := filepath.Join(testDir, "secrets")
+	if err := os.MkdirAll(subDir, 0o755); err != nil {
+		t.Fatalf("creating dirs: %v", err)
+	}
+
+	normalFile := filepath.Join(testDir, "settings.yaml")
+	secretFile := filepath.Join(subDir, "token.key")
+	if err := os.WriteFile(normalFile, []byte("settings"), 0o644); err != nil {
+		t.Fatalf("writing normal file: %v", err)
+	}
+	if err := os.WriteFile(secretFile, []byte("token"), 0o600); err != nil {
+		t.Fatalf("writing secret file: %v", err)
+	}
+
+	// Exclude the entire secrets subdirectory.
+	if err := g.Exclude([]string{subDir}); err != nil {
+		t.Fatalf("Exclude: %v", err)
+	}
+
+	if err := g.Add([]string{testDir}); err != nil {
+		t.Fatalf("Add: %v", err)
+	}
+
+	if len(g.manifest.Files) != 1 {
+		t.Fatalf("expected 1 file, got %d", len(g.manifest.Files))
+	}
+
+	expectedPath := toTildePath(normalFile)
+	if g.manifest.Files[0].Path != expectedPath {
+		t.Errorf("tracked file = %q, want %q", g.manifest.Files[0].Path, expectedPath)
+	}
+}
+
+func TestMirrorUpSkipsExcluded(t *testing.T) {
+	root := t.TempDir()
+	repoDir := filepath.Join(root, "repo")
+
+	g, err := Init(repoDir)
+	if err != nil {
+		t.Fatalf("Init: %v", err)
+	}
+
+	testDir := filepath.Join(root, "config")
+	if err := os.MkdirAll(testDir, 0o755); err != nil {
+		t.Fatalf("creating dir: %v", err)
+	}
+
+	normalFile := filepath.Join(testDir, "settings.yaml")
+	secretFile := filepath.Join(testDir, "credentials.key")
+	if err := os.WriteFile(normalFile, []byte("settings"), 0o644); err != nil {
+		t.Fatalf("writing normal file: %v", err)
+	}
+	if err := os.WriteFile(secretFile, []byte("secret"), 0o600); err != nil {
+		t.Fatalf("writing secret file: %v", err)
+	}
+
+	// Exclude the secret file.
+	if err := g.Exclude([]string{secretFile}); err != nil {
+		t.Fatalf("Exclude: %v", err)
+	}
+
+	if err := g.MirrorUp([]string{testDir}); err != nil {
+		t.Fatalf("MirrorUp: %v", err)
+	}
+
+	// Only the normal file should be tracked.
+	if len(g.manifest.Files) != 1 {
+		t.Fatalf("expected 1 file, got %d", len(g.manifest.Files))
+	}
+
+	expectedPath := toTildePath(normalFile)
+	if g.manifest.Files[0].Path != expectedPath {
+		t.Errorf("tracked file = %q, want %q", g.manifest.Files[0].Path, expectedPath)
+	}
+}
+
+func TestMirrorDownLeavesExcludedAlone(t *testing.T) {
+	root := t.TempDir()
+	repoDir := filepath.Join(root, "repo")
+
+	g, err := Init(repoDir)
+	if err != nil {
+		t.Fatalf("Init: %v", err)
+	}
+
+	testDir := filepath.Join(root, "config")
+	if err := os.MkdirAll(testDir, 0o755); err != nil {
+		t.Fatalf("creating dir: %v", err)
+	}
+
+	normalFile := filepath.Join(testDir, "settings.yaml")
+	secretFile := filepath.Join(testDir, "credentials.key")
+	if err := os.WriteFile(normalFile, []byte("settings"), 0o644); err != nil {
+		t.Fatalf("writing normal file: %v", err)
+	}
+	if err := os.WriteFile(secretFile, []byte("secret"), 0o600); err != nil {
+		t.Fatalf("writing secret file: %v", err)
+	}
+
+	// Add only the normal file.
+	if err := g.Add([]string{normalFile}); err != nil {
+		t.Fatalf("Add: %v", err)
+	}
+
+	// Exclude the secret file.
+	if err := g.Exclude([]string{secretFile}); err != nil {
+		t.Fatalf("Exclude: %v", err)
+	}
+
+	// MirrorDown with force — excluded file should NOT be deleted.
+	if err := g.MirrorDown([]string{testDir}, true, nil); err != nil {
+		t.Fatalf("MirrorDown: %v", err)
+	}
+
+	if _, err := os.Stat(secretFile); err != nil {
+		t.Error("excluded file should not have been deleted by MirrorDown")
+	}
+}
+
+func TestIsExcludedDirectoryPrefix(t *testing.T) {
+	root := t.TempDir()
+	repoDir := filepath.Join(root, "repo")
+
+	g, err := Init(repoDir)
+	if err != nil {
+		t.Fatalf("Init: %v", err)
+	}
+
+	// Exclude a directory.
+	g.manifest.Exclude = []string{"~/config/secrets"}
+
+	if !g.manifest.IsExcluded("~/config/secrets") {
+		t.Error("exact match should be excluded")
+	}
+	if !g.manifest.IsExcluded("~/config/secrets/token.key") {
+		t.Error("file under excluded dir should be excluded")
+	}
+	if !g.manifest.IsExcluded("~/config/secrets/nested/deep.key") {
+		t.Error("deeply nested file under excluded dir should be excluded")
+	}
+	if g.manifest.IsExcluded("~/config/secrets-backup/file.key") {
+		t.Error("path with similar prefix but different dir should not be excluded")
+	}
+	if g.manifest.IsExcluded("~/config/other.yaml") {
+		t.Error("unrelated path should not be excluded")
+	}
+}

garden/garden.go

@@ -256,6 +256,13 @@ func (g *Garden) Add(paths []string, opts ...AddOptions) error {
 					if err != nil {
 						return err
 					}
+					tilded := toTildePath(path)
+					if g.manifest.IsExcluded(tilded) {
+						if d.IsDir() {
+							return filepath.SkipDir
+						}
+						return nil
+					}
 					if d.IsDir() {
 						return nil
 					}

garden/mirror.go

@@ -30,6 +30,13 @@ func (g *Garden) MirrorUp(paths []string) error {
 			if walkErr != nil {
 				return walkErr
 			}
+			tilded := toTildePath(path)
+			if g.manifest.IsExcluded(tilded) {
+				if d.IsDir() {
+					return filepath.SkipDir
+				}
+				return nil
+			}
 			if d.IsDir() {
 				return nil
 			}
@@ -154,6 +161,9 @@ func (g *Garden) MirrorDown(paths []string, force bool, confirm func(string) boo
 				return walkErr
 			}
 			if d.IsDir() {
+				if g.manifest.IsExcluded(toTildePath(path)) {
+					return filepath.SkipDir
+				}
 				// Collect directories for potential cleanup (post-order).
 				if path != abs {
 					emptyDirs = append(emptyDirs, path)
@@ -163,6 +173,10 @@ func (g *Garden) MirrorDown(paths []string, force bool, confirm func(string) boo
 			if tracked[path] {
 				return nil
 			}
+			// Excluded paths are left alone on disk.
+			if g.manifest.IsExcluded(toTildePath(path)) {
+				return nil
+			}
 			// Untracked file/symlink on disk.
 			if !force {
 				if confirm == nil || !confirm(path) {