Merge pull request #135000 from p0lyn0mial/upstream-watchlist-unsupported-wl-semantics-trackers

k8s.io/client-go/testing/fixture: does not support WatchList semantics

staging/src/k8s.io/client-go/testing/fixture.go

@@ -511,6 +511,17 @@ func (t *tracker) Apply(gvr schema.GroupVersionResource, applyConfiguration runt
 	return t.add(gvr, obj, ns, true)
 }
 
+// IsWatchListSemanticsUnSupported informs the reflector that this client
+// doesn't support WatchList semantics.
+//
+// This is a synthetic method whose sole purpose is to satisfy the optional
+// interface check performed by the reflector.
+// Returning true signals that WatchList can NOT be used.
+// No additional logic is implemented here.
+func (t *tracker) IsWatchListSemanticsUnSupported() bool {
+	return true
+}
+
 func (t *tracker) getWatches(gvr schema.GroupVersionResource, ns string) []*watch.RaceFreeFakeWatcher {
 	watches := []*watch.RaceFreeFakeWatcher{}
 	if t.watchers[gvr] != nil {

staging/src/k8s.io/client-go/testing/fixture_test.go

@@ -39,6 +39,7 @@ import (
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/apimachinery/pkg/util/managedfields"
 	"k8s.io/apimachinery/pkg/watch"
+	"k8s.io/client-go/util/watchlist"
 	"k8s.io/utils/ptr"
 )
 
@@ -740,3 +741,14 @@ func TestManagedFielsdObjectTrackerWithUnstructured(t *testing.T) {
 	unstructured.RemoveNestedField(cmActual.Object, "metadata", "managedFields")
 	require.Empty(t, cmp.Diff(cmOriginal, cmActual))
 }
+
+func TestDoesClientSupportWatchListSemantics(t *testing.T) {
+	scheme := runtime.NewScheme()
+	codecs := serializer.NewCodecFactory(scheme)
+
+	target := NewObjectTracker(scheme, codecs.UniversalDecoder())
+
+	if !watchlist.DoesClientNotSupportWatchListSemantics(target) {
+		t.Fatalf("ObjectTracker should NOT support WatchList semantics")
+	}
+}