w.Unlock()

	if ok {
		ch <- err
	}
}

// NewFakeWatcher returns a function which creates a new fake watcher for unit
// testing. This allows observe callers to inject events and errors per-watched
// path. changedFunc() provides a callback notification when a new watch is added
// or removed. Production code should use `NewWatcher()`.
func NewFakeWatcher(changedFunc func(path string, added bool)) (NewFileWatcherFunc, *FakeWatcher) {

type fakeWatcher struct {
	watches      []string // List of watches added by the prober, ordered from least recent to most recent.
	eventHandler utilfs.FSEventHandler
}

var _ utilfs.FSWatcher = &fakeWatcher{}

func newFakeWatcher() *fakeWatcher {
	return &fakeWatcher{
		watches: nil,
	}
}

func (w *fakeWatcher) Init(eventHandler utilfs.FSEventHandler, _ utilfs.FSErrorHandler) error {
	w.eventHandler = eventHandler
	return nil
}

	assert.NoError(t, err)
}

// Tests the behavior when no drivers exist in the plugin directory.
func TestEmptyPluginDir(t *testing.T) {
	// Arrange
	fs := utilfs.NewTempFs()
	watcher := newFakeWatcher()
	prober := &flexVolumeProber{
		pluginDir: pluginDir,
		watcher:   watcher,
		fs:        fs,
		factory:   fakePluginFactory{},
	}
	prober.Init()

	// Act
	events, err := prober.Probe()

	removedChan := make(chan string, 10)

	changed := func(path string, added bool) {
		if added {
			addedChan <- path
		} else {
			removedChan <- path
		}
	}

	newWatcher, fakeWatcher := NewFakeWatcher(changed)
	watcher := newWatcher()

	// verify Add()/Remove()
	for _, file := range []string{"foo", "bar", "baz"} {
		if err := watcher.Add(file); err != nil {
			t.Fatalf("Add() returned error: %v", err)
		}

	}
}

func GetDynamicPluginProberWithoutWatcher(pluginDir string, runner exec.Interface) volume.DynamicPluginProber {
	return &flexVolumeProber{
		pluginDir: pluginDir,
		watcher:   newFakeWatcher(),
		factory:   pluginFactory{},
		runner:    runner,
		fs:        &utilfs.DefaultFs{},
	}