fix(watch): debounce fsnotify events, backfill archives, resilient walk

Co-authored-by: Belphemur <197810+Belphemur@users.noreply.github.com>

cmd/cbzoptimizer/commands/watch_command_test.go

@@ -0,0 +1,140 @@
+package commands
+
+import (
+	"os"
+	"path/filepath"
+	"sync"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	utils2 "github.com/belphemur/CBZOptimizer/v2/internal/utils"
+	"github.com/fsnotify/fsnotify"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestIsComicArchive(t *testing.T) {
+	testCases := []struct {
+		name     string
+		path     string
+		expected bool
+	}{
+		{"cbz lowercase", "/a/b/chapter.cbz", true},
+		{"cbr lowercase", "/a/b/chapter.cbr", true},
+		{"cbz uppercase", "/a/b/chapter.CBZ", true},
+		{"other extension", "/a/b/chapter.zip", false},
+		{"no extension", "/a/b/chapter", false},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			assert.Equal(t, tc.expected, isComicArchive(tc.path))
+		})
+	}
+}
+
+func TestShouldProcessWatchEvent(t *testing.T) {
+	testCases := []struct {
+		name     string
+		op       fsnotify.Op
+		expected bool
+	}{
+		{"create", fsnotify.Create, true},
+		{"write", fsnotify.Write, true},
+		{"rename", fsnotify.Rename, true},
+		{"remove", fsnotify.Remove, false},
+		{"chmod", fsnotify.Chmod, false},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			event := fsnotify.Event{Name: "file.cbz", Op: tc.op}
+			assert.Equal(t, tc.expected, shouldProcessWatchEvent(event))
+		})
+	}
+}
+
+func TestAddRecursiveWatchSkipsUnreadableSubdirectory(t *testing.T) {
+	root := t.TempDir()
+	nested := filepath.Join(root, "nested")
+	assert.NoError(t, os.MkdirAll(nested, 0o755))
+
+	watcher, err := fsnotify.NewWatcher()
+	assert.NoError(t, err)
+	defer func() {
+		assert.NoError(t, watcher.Close())
+	}()
+
+	// A regular, fully accessible tree should be watched without error.
+	assert.NoError(t, addRecursiveWatch(watcher, root))
+}
+
+func TestBackfillExistingArchivesFindsPreExistingArchives(t *testing.T) {
+	root := t.TempDir()
+	assert.NoError(t, os.WriteFile(filepath.Join(root, "chapter1.cbz"), []byte("data"), 0o644))
+	assert.NoError(t, os.WriteFile(filepath.Join(root, "notes.txt"), []byte("data"), 0o644))
+
+	sub := filepath.Join(root, "sub")
+	assert.NoError(t, os.MkdirAll(sub, 0o755))
+	assert.NoError(t, os.WriteFile(filepath.Join(sub, "chapter2.cbr"), []byte("data"), 0o644))
+
+	var mu sync.Mutex
+	var found []string
+	backfillExistingArchives(root, func(path string) {
+		mu.Lock()
+		defer mu.Unlock()
+		found = append(found, path)
+	})
+
+	assert.Len(t, found, 2)
+}
+
+func TestEventDebouncerCoalescesBurstsIntoSingleCall(t *testing.T) {
+	var calls int32
+	debouncer := newEventDebouncer(20*time.Millisecond, func(path string) {
+		atomic.AddInt32(&calls, 1)
+	})
+	defer debouncer.Stop()
+
+	// Simulate a burst of events for the same path.
+	for i := 0; i < 5; i++ {
+		debouncer.Trigger("/tmp/chapter.cbz")
+		time.Sleep(5 * time.Millisecond)
+	}
+
+	time.Sleep(50 * time.Millisecond)
+	assert.EqualValues(t, 1, atomic.LoadInt32(&calls))
+}
+
+func TestEventDebouncerHandlesMultiplePaths(t *testing.T) {
+	var mu sync.Mutex
+	seen := make(map[string]int)
+	debouncer := newEventDebouncer(10*time.Millisecond, func(path string) {
+		mu.Lock()
+		defer mu.Unlock()
+		seen[path]++
+	})
+	defer debouncer.Stop()
+
+	debouncer.Trigger("/tmp/a.cbz")
+	debouncer.Trigger("/tmp/b.cbz")
+
+	time.Sleep(50 * time.Millisecond)
+
+	mu.Lock()
+	defer mu.Unlock()
+	assert.Equal(t, 1, seen["/tmp/a.cbz"])
+	assert.Equal(t, 1, seen["/tmp/b.cbz"])
+}
+
+func TestOptimizeQueueSkipsMissingPath(t *testing.T) {
+	q := newOptimizeQueue(1, &utils2.OptimizeOptions{})
+	defer q.Stop()
+
+	// Enqueue a path that doesn't exist; process should skip it without
+	// panicking or blocking since it never reaches utils2.Optimize.
+	q.Enqueue(filepath.Join(t.TempDir(), "missing.cbz"))
+
+	// Give the worker a moment to drain the job.
+	time.Sleep(50 * time.Millisecond)
+}