Use private option for newInformer override

Author: maxsmythe

pkg/cache/cache.go

@@ -44,6 +44,7 @@ var (
 	defaultSyncPeriod = 10 * time.Hour
 )
 
+// InformerGetOptions defines the behavior of how informers are retrieved.
 type InformerGetOptions internal.GetOptions
 
 // InformerGetOption defines an option that alters the behavior of how informers are retrieved.
@@ -201,8 +202,8 @@ type Options struct {
 	// object, this will fall through to Default* settings.
 	ByObject map[client.Object]ByObject
 
-	// NewInformer allows overriding of NewSharedIndexInformer for testing.
-	NewInformer func(toolscache.ListerWatcher, runtime.Object, time.Duration, toolscache.Indexers) toolscache.SharedIndexInformer
+	// newInformer allows overriding of NewSharedIndexInformer for testing.
+	newInformer *func(toolscache.ListerWatcher, runtime.Object, time.Duration, toolscache.Indexers) toolscache.SharedIndexInformer
 }
 
 // ByObject offers more fine-grained control over the cache's ListWatch by object.
@@ -353,7 +354,7 @@ func newCache(restConfig *rest.Config, opts Options) newCacheFunc {
 				},
 				Transform:             config.Transform,
 				UnsafeDisableDeepCopy: pointer.BoolDeref(config.UnsafeDisableDeepCopy, false),
-				NewInformer:           opts.NewInformer,
+				NewInformer:           opts.newInformer,
 			}),
 			readerFailOnMissingInformer: opts.ReaderFailOnMissingInformer,
 		}

pkg/cache/cache_test.go

@@ -119,11 +119,7 @@ func deletePod(pod client.Object) {
 
 var _ = Describe("Informer Cache", func() {
 	CacheTest(cache.New, cache.Options{})
-	NonBlockingGetTest(cache.New, cache.Options{
-		NewInformer: func(lw kcache.ListerWatcher, o runtime.Object, d time.Duration, i kcache.Indexers) kcache.SharedIndexInformer {
-			return &controllertest.FakeInformer{Synced: false}
-		},
-	})
+	NonBlockingGetTest(cache.New, cache.Options{})
 })
 
 var _ = Describe("Informer Cache with ReaderFailOnMissingInformer", func() {
@@ -144,9 +140,6 @@ var _ = Describe("Multi-Namespace Informer Cache", func() {
 			testNamespaceTwo: {},
 			"default":        {},
 		},
-		NewInformer: func(lw kcache.ListerWatcher, o runtime.Object, d time.Duration, i kcache.Indexers) kcache.SharedIndexInformer {
-			return &controllertest.FakeInformer{Synced: false}
-		},
 	})
 })
 
@@ -156,9 +149,6 @@ var _ = Describe("Informer Cache without global DeepCopy", func() {
 	})
 	NonBlockingGetTest(cache.New, cache.Options{
 		DefaultUnsafeDisableDeepCopy: pointer.Bool(true),
-		NewInformer: func(lw kcache.ListerWatcher, o runtime.Object, d time.Duration, i kcache.Indexers) kcache.SharedIndexInformer {
-			return &controllertest.FakeInformer{Synced: false}
-		},
 	})
 })
 
@@ -553,6 +543,14 @@ func NonBlockingGetTest(createCacheFunc func(config *rest.Config, opts cache.Opt
 			Expect(err).NotTo(HaveOccurred())
 
 			By("creating the informer cache")
+			v := reflect.ValueOf(&opts).Elem()
+			newInformerField := v.FieldByName("newInformer")
+			newFakeInformer := func(lw kcache.ListerWatcher, o runtime.Object, d time.Duration, i kcache.Indexers) kcache.SharedIndexInformer {
+				return &controllertest.FakeInformer{Synced: false}
+			}
+			reflect.NewAt(newInformerField.Type(), newInformerField.Addr().UnsafePointer()). //nolint:gosec // overriding informer with one that is guaranteed to block.
+														Elem().
+														Set(reflect.ValueOf(&newFakeInformer))
 			informerCache, err = createCacheFunc(cfg, opts)
 			Expect(err).NotTo(HaveOccurred())
 			By("running the cache and waiting for it to sync")

pkg/cache/internal/informers.go

@@ -45,7 +45,7 @@ type InformersOpts struct {
 	Mapper                meta.RESTMapper
 	ResyncPeriod          time.Duration
 	Namespace             string
-	NewInformer           func(cache.ListerWatcher, runtime.Object, time.Duration, cache.Indexers) cache.SharedIndexInformer
+	NewInformer           *func(cache.ListerWatcher, runtime.Object, time.Duration, cache.Indexers) cache.SharedIndexInformer
 	Selector              Selector
 	Transform             cache.TransformFunc
 	UnsafeDisableDeepCopy bool
@@ -55,7 +55,7 @@ type InformersOpts struct {
 func NewInformers(config *rest.Config, options *InformersOpts) *Informers {
 	newInformer := cache.NewSharedIndexInformer
 	if options.NewInformer != nil {
-		newInformer = options.NewInformer
+		newInformer = *options.NewInformer
 	}
 	return &Informers{
 		config:     config,