Deflake TestListResourceVersion0

Author: liggitt

test/integration/apiserver/BUILD

@@ -54,6 +54,7 @@ go_test(
         "//staging/src/k8s.io/apimachinery/pkg/runtime/serializer/protobuf:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/runtime/serializer/streaming:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/types:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/util/wait:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/watch:go_default_library",
         "//staging/src/k8s.io/apiserver/pkg/features:go_default_library",
         "//staging/src/k8s.io/apiserver/pkg/util/feature:go_default_library",

test/integration/apiserver/apiserver_test.go

@@ -49,6 +49,7 @@ import (
 	"k8s.io/apimachinery/pkg/runtime/serializer/protobuf"
 	"k8s.io/apimachinery/pkg/runtime/serializer/streaming"
 	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/apimachinery/pkg/util/wait"
 	"k8s.io/apimachinery/pkg/watch"
 	"k8s.io/apiserver/pkg/features"
 	utilfeature "k8s.io/apiserver/pkg/util/feature"
@@ -548,6 +549,20 @@ func TestListResourceVersion0(t *testing.T) {
 				}
 			}
 
+			if tc.watchCacheEnabled {
+				// poll until the watch cache has the full list in memory
+				err := wait.PollImmediate(time.Second, wait.ForeverTestTimeout, func() (bool, error) {
+					list, err := clientSet.AppsV1().ReplicaSets(ns.Name).List(context.Background(), metav1.ListOptions{ResourceVersion: "0"})
+					if err != nil {
+						return false, err
+					}
+					return len(list.Items) == 10, nil
+				})
+				if err != nil {
+					t.Fatalf("error waiting for watch cache to observe the full list: %v", err)
+				}
+			}
+
 			pagerFn := func(opts metav1.ListOptions) (runtime.Object, error) {
 				return rsClient.List(context.TODO(), opts)
 			}