feat(watcher): enhance .ndignore handling for folder deletions and file changes

Signed-off-by: Deluan <deluan@navidrome.org>

scanner/watcher.go

@@ -225,13 +225,18 @@ func (w *watcher) watchLibrary(ctx context.Context, lib *model.Library) error {
 
 	log.Info(ctx, "Watcher started for library", "libraryID", lib.ID, "name", lib.Name, "path", lib.Path, "absoluteLibPath", absLibPath)
 
+	return w.processLibraryEvents(ctx, lib, fsys, c, absLibPath)
+}
+
+// processLibraryEvents processes filesystem events for a library.
+func (w *watcher) processLibraryEvents(ctx context.Context, lib *model.Library, fsys storage.MusicFS, events <-chan string, absLibPath string) error {
 	for {
 		select {
 		case <-ctx.Done():
 			log.Debug(ctx, "Watcher stopped due to context cancellation", "libraryID", lib.ID, "name", lib.Name)
 			return nil
-		case path := <-c:
-			path, err = filepath.Rel(absLibPath, path)
+		case path := <-events:
+			path, err := filepath.Rel(absLibPath, path)
 			if err != nil {
 				log.Error(ctx, "Error getting relative path", "libraryID", lib.ID, "absolutePath", absLibPath, "path", path, err)
 				continue
@@ -243,9 +248,18 @@ func (w *watcher) watchLibrary(ctx context.Context, lib *model.Library) error {
 			}
 			log.Trace(ctx, "Detected change", "libraryID", lib.ID, "path", path, "absoluteLibPath", absLibPath)
 
+			// Check if the original path (before resolution) matches .ndignore patterns
+			// This is crucial for deleted folders - if a deleted folder matches .ndignore,
+			// we should ignore it BEFORE resolveFolderPath walks up to the parent
+			if w.shouldIgnoreFolderPath(ctx, fsys, path) {
+				log.Debug(ctx, "Ignoring change matching .ndignore pattern", "libraryID", lib.ID, "path", path)
+				continue
+			}
+
 			// Find the folder to scan - validate path exists as directory, walk up if needed
 			folderPath := resolveFolderPath(fsys, path)
-			if w.shouldIgnoreFolderPath(ctx, fsys, folderPath) {
+			// Double-check after resolution in case the resolved path is different and also matches patterns
+			if folderPath != path && w.shouldIgnoreFolderPath(ctx, fsys, folderPath) {
 				log.Trace(ctx, "Ignoring change in folder matching .ndignore pattern", "libraryID", lib.ID, "folderPath", folderPath)
 				continue
 			}

scanner/watcher_test.go

@@ -3,6 +3,7 @@ package scanner
 import (
 	"context"
 	"io/fs"
+	"path/filepath"
 	"testing/fstest"
 	"time"
 
@@ -276,6 +277,159 @@ var _ = Describe("Watcher", func() {
 			Expect(libraryIDs).To(HaveKey(2))
 		})
 	})
+
+	Describe(".ndignore handling", func() {
+		var ctx context.Context
+		var cancel context.CancelFunc
+		var w *watcher
+		var mockFS *mockMusicFS
+		var lib *model.Library
+		var eventChan chan string
+		var absLibPath string
+
+		BeforeEach(func() {
+			ctx, cancel = context.WithCancel(GinkgoT().Context())
+			DeferCleanup(cancel)
+
+			// Set up library
+			var err error
+			absLibPath, err = filepath.Abs(".")
+			Expect(err).NotTo(HaveOccurred())
+
+			lib = &model.Library{
+				ID:   1,
+				Name: "Test Library",
+				Path: absLibPath,
+			}
+
+			// Create watcher with notification channel
+			w = &watcher{
+				watcherNotify: make(chan scanNotification, 10),
+			}
+
+			eventChan = make(chan string, 10)
+		})
+
+		// Helper to send an event - converts relative path to absolute
+		sendEvent := func(relativePath string) {
+			path := filepath.Join(absLibPath, relativePath)
+			eventChan <- path
+		}
+
+		// Helper to start the real event processing loop
+		startEventProcessing := func() {
+			go func() {
+				defer GinkgoRecover()
+				// Call the actual processLibraryEvents method - testing the real implementation!
+				_ = w.processLibraryEvents(ctx, lib, mockFS, eventChan, absLibPath)
+			}()
+		}
+
+		Context("when a folder matching .ndignore is deleted", func() {
+			BeforeEach(func() {
+				// Create filesystem with .ndignore containing _TEMP pattern
+				// The deleted folder (_TEMP) will NOT exist in the filesystem
+				mockFS = &mockMusicFS{
+					FS: fstest.MapFS{
+						"rock":                       &fstest.MapFile{Mode: fs.ModeDir},
+						"rock/.ndignore":             &fstest.MapFile{Data: []byte("_TEMP\n")},
+						"rock/valid_album":           &fstest.MapFile{Mode: fs.ModeDir},
+						"rock/valid_album/track.mp3": &fstest.MapFile{Data: []byte("audio")},
+					},
+				}
+			})
+
+			It("should NOT send scan notification when deleted folder matches .ndignore", func() {
+				startEventProcessing()
+
+				// Simulate deletion event for rock/_TEMP
+				sendEvent("rock/_TEMP")
+
+				// Wait a bit to ensure event is processed
+				time.Sleep(50 * time.Millisecond)
+
+				// No notification should have been sent
+				Consistently(eventChan, 100*time.Millisecond).Should(BeEmpty())
+			})
+
+			It("should send scan notification for valid folder deletion", func() {
+				startEventProcessing()
+
+				// Simulate deletion event for rock/other_folder (not in .ndignore and doesn't exist)
+				// Since it doesn't exist in mockFS, resolveFolderPath will walk up to "rock"
+				sendEvent("rock/other_folder")
+
+				// Should receive notification for parent folder
+				Eventually(w.watcherNotify, 200*time.Millisecond).Should(Receive(Equal(scanNotification{
+					Library:    lib,
+					FolderPath: "rock",
+				})))
+			})
+		})
+
+		Context("with nested folder patterns", func() {
+			BeforeEach(func() {
+				mockFS = &mockMusicFS{
+					FS: fstest.MapFS{
+						"music":             &fstest.MapFile{Mode: fs.ModeDir},
+						"music/.ndignore":   &fstest.MapFile{Data: []byte("**/temp\n**/cache\n")},
+						"music/rock":        &fstest.MapFile{Mode: fs.ModeDir},
+						"music/rock/artist": &fstest.MapFile{Mode: fs.ModeDir},
+					},
+				}
+			})
+
+			It("should NOT send notification when nested ignored folder is deleted", func() {
+				startEventProcessing()
+
+				// Simulate deletion of music/rock/artist/temp (matches **/temp)
+				sendEvent("music/rock/artist/temp")
+
+				// Wait to ensure event is processed
+				time.Sleep(50 * time.Millisecond)
+
+				// No notification should be sent
+				Expect(w.watcherNotify).To(BeEmpty(), "Expected no scan notification for nested ignored folder")
+			})
+
+			It("should send notification for non-ignored nested folder", func() {
+				startEventProcessing()
+
+				// Simulate change in music/rock/artist (doesn't match any pattern)
+				sendEvent("music/rock/artist")
+
+				// Should receive notification
+				Eventually(w.watcherNotify, 200*time.Millisecond).Should(Receive(Equal(scanNotification{
+					Library:    lib,
+					FolderPath: "music/rock/artist",
+				})))
+			})
+		})
+
+		Context("with file events in ignored folders", func() {
+			BeforeEach(func() {
+				mockFS = &mockMusicFS{
+					FS: fstest.MapFS{
+						"rock":           &fstest.MapFile{Mode: fs.ModeDir},
+						"rock/.ndignore": &fstest.MapFile{Data: []byte("_TEMP\n")},
+					},
+				}
+			})
+
+			It("should NOT send notification for file changes in ignored folders", func() {
+				startEventProcessing()
+
+				// Simulate file change in rock/_TEMP/file.mp3
+				sendEvent("rock/_TEMP/file.mp3")
+
+				// Wait to ensure event is processed
+				time.Sleep(50 * time.Millisecond)
+
+				// No notification should be sent
+				Expect(w.watcherNotify).To(BeEmpty(), "Expected no scan notification for file in ignored folder")
+			})
+		})
+	})
 })
 
 var _ = Describe("resolveFolderPath", func() {