refactor: clean up code (#5308)

pkg/util/wait/backoff_test.go

@@ -0,0 +1,27 @@
+package wait
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+	clocktesting "k8s.io/utils/clock/testing"
+)
+
+func TestFastBackoffManagerUsesClock(t *testing.T) {
+	require := require.New(t)
+
+	start := time.Date(2026, time.May, 8, 12, 30, 0, 0, time.UTC)
+	clk := clocktesting.NewFakeClock(start)
+	backoff := newFastBackoffManagerWithClock(FastBackoffOptions{
+		Duration: time.Second,
+	}, clk).(*fastBackoffImpl)
+
+	require.Equal(time.Second, backoff.Backoff(0, false))
+	require.Equal(start, backoff.lastCalledTime)
+
+	next := start.Add(time.Minute)
+	clk.SetTime(next)
+	require.Equal(time.Second, backoff.Backoff(time.Second, false))
+	require.Equal(next, backoff.lastCalledTime)
+}