labeler: use wait in test, not sleep

Signed-off-by: Tuomas Katila <[email protected]>

Author: tkatila

cmd/internal/labeler/labeler_test.go

@@ -24,6 +24,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/fsnotify/fsnotify"
 	"github.com/intel/intel-device-plugins-for-kubernetes/cmd/internal/pluginutils"
 )
 
@@ -715,6 +716,31 @@ func TestCreateAndRun(t *testing.T) {
 		CreateAndPrintLabels(sysfs)
 	})
 
+	waitForFileOp := func(directory, file string, eventType fsnotify.Op, duration time.Duration) bool {
+		watcher, err := fsnotify.NewWatcher()
+		if err != nil {
+			t.Fatal(err)
+		}
+		defer watcher.Close()
+
+		if err := watcher.Add(directory); err != nil {
+			t.Fatal(err)
+		}
+
+		timer := time.NewTimer(duration)
+
+		for {
+			select {
+			case event := <-watcher.Events:
+				if filepath.Base(event.Name) == file && event.Has(eventType) {
+					return true
+				}
+			case <-timer.C:
+				return false
+			}
+		}
+	}
+
 	t.Run("Run", func(t *testing.T) {
 		err := os.MkdirAll(path.Join(subroot, "0"), 0750)
 		if err != nil {
@@ -726,16 +752,13 @@ func TestCreateAndRun(t *testing.T) {
 
 		c := make(chan bool, 1)
 
-		nfdLabelFile := filepath.Join(root, "nfd-labelfile.txt")
+		nfdLabelBase := "nfd-labelfile.txt"
+		nfdLabelFile := filepath.Join(root, nfdLabelBase)
 
 		go Run(sysfs, nfdLabelFile, time.Millisecond, c, nil, func() {})
 
 		// Wait for the labeling timeout to trigger
-		time.Sleep(time.Millisecond * 2)
-
-		// Make sure the file has been created
-		_, err = os.Stat(nfdLabelFile)
-		if err != nil {
+		if !waitForFileOp(root, nfdLabelBase, fsnotify.Create, time.Second*2) {
 			t.Error("Run didn't create label file")
 		}
 
@@ -744,12 +767,9 @@ func TestCreateAndRun(t *testing.T) {
 			t.Error("Calling Kill failed")
 		}
 
-		time.Sleep(time.Millisecond * 2)
-
-		// Make sure the label file has been deleted
-		_, err = os.Stat(nfdLabelFile)
-		if err == nil {
-			t.Error("Run didn't remove label file on exit")
+		// Wait for the labeling timeout to trigger
+		if !waitForFileOp(root, nfdLabelBase, fsnotify.Remove, time.Second*2) {
+			t.Error("Run didn't remove label file")
 		}
 	})
 }