Merge pull request #135324 from p0lyn0mial/upstream-watchlist-unsupported-wl-better-docs

client-go/reflector: Improve WatchListClient disabled log message for clarity

staging/src/k8s.io/client-go/tools/cache/reflector.go

@@ -302,8 +302,7 @@ func NewReflectorWithOptions(lw ListerWatcher, expectedType interface{}, store R
 		// Using klog.TODO() here because switching to a caller-provided contextual logger
 		// would require an API change and updating all existing call sites.
 		klog.TODO().V(2).Info(
-			"The provided ListWatcher doesn't support WatchList semantics. The feature will be disabled. If you are using a custom client, check the documentation of watchlist.DoesClientNotSupportWatchListSemantics() method",
-			"listWatcherType", fmt.Sprintf("%T", lw),
+			"The client used to build this informer/reflector doesn't support WatchList semantics. The feature will be disabled. This is expected in unit tests but not in production. For details, see the documentation of watchlist.DoesClientNotSupportWatchListSemantics().",
 			"feature", clientfeatures.WatchListClient,
 		)
 		r.useWatchList = false

staging/src/k8s.io/client-go/util/watchlist/watch_list.go

@@ -90,6 +90,9 @@ type unSupportedWatchListSemantics interface {
 //
 // A client does NOT support WatchList only if
 // it implements `IsWatchListSemanticsUnSupported` and that returns true.
+//
+// For an explanation of how WatchList works, see:
+// https://kubernetes.io/docs/reference/using-api/api-concepts/#streaming-lists
 func DoesClientNotSupportWatchListSemantics(client any) bool {
 	lw, ok := client.(unSupportedWatchListSemantics)
 	if !ok {