install watch reaction function to fake client

testing/aliases.go

@@ -22,6 +22,8 @@ import (
 
 type Reactor = clientgotesting.Reactor
 type ReactionFunc = clientgotesting.ReactionFunc
+type WatchReactor = clientgotesting.WatchReactor
+type WatchReactionFunc = clientgotesting.WatchReactionFunc
 
 type Action = clientgotesting.Action
 type GetAction = clientgotesting.GetAction

testing/client.go

@@ -23,10 +23,13 @@ import (
 
 	"k8s.io/apimachinery/pkg/api/meta"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apimachinery/pkg/watch"
 	clientgotesting "k8s.io/client-go/testing"
 	ref "k8s.io/client-go/tools/reference"
+	"reconciler.io/runtime/duck"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 )
 
@@ -50,6 +53,7 @@ type clientWrapper struct {
 	StatusPatchActions      []PatchAction
 	genCount                int
 	reactionChain           []Reactor
+	watchReactionChain      []WatchReactor
 }
 
 var _ TestClient = (*clientWrapper)(nil)
@@ -67,6 +71,7 @@ func NewFakeClientWrapper(client client.Client, tracker clientgotesting.ObjectTr
 		StatusPatchActions:      []PatchAction{},
 		genCount:                0,
 		reactionChain:           []Reactor{},
+		watchReactionChain:      []WatchReactor{},
 	}
 	// generate names on create
 	c.AddReactor("create", "*", func(action Action) (bool, runtime.Object, error) {
@@ -115,6 +120,10 @@ func (w *clientWrapper) PrependReactor(verb, kind string, reaction ReactionFunc)
 	w.reactionChain = append([]Reactor{&clientgotesting.SimpleReactor{Verb: verb, Resource: kind, Reaction: reaction}}, w.reactionChain...)
 }
 
+func (w *clientWrapper) PrependWatchReactor(kind string, reaction WatchReactionFunc) {
+	w.watchReactionChain = append([]WatchReactor{&clientgotesting.SimpleWatchReactor{Resource: kind, Reaction: reaction}}, w.watchReactionChain...)
+}
+
 func (w *clientWrapper) objmeta(obj runtime.Object) (schema.GroupVersionResource, string, string, error) {
 	objref, err := ref.GetReference(w.Scheme(), obj)
 	if err != nil {
@@ -140,6 +149,20 @@ func (w *clientWrapper) react(action Action) error {
 	return nil
 }
 
+func (w *clientWrapper) reactWatcherFunc(action Action) error {
+	for _, reactor := range w.watchReactionChain {
+		if !reactor.Handles(action) {
+			continue
+		}
+		handled, _, err := reactor.React(action)
+		if !handled {
+			continue
+		}
+		return err
+	}
+	return nil
+}
+
 func (w *clientWrapper) Scheme() *runtime.Scheme {
 	return w.client.Scheme()
 }
@@ -307,6 +330,55 @@ func (w *clientWrapper) DeleteAllOf(ctx context.Context, obj client.Object, opts
 	return w.client.DeleteAllOf(ctx, obj, opts...)
 }
 
+func (w *clientWrapper) Watch(ctx context.Context, list client.ObjectList, opts ...client.ListOption) (watch.Interface, error) {
+
+	ww, ok := w.client.(client.WithWatch)
+	if !ok {
+		panic(fmt.Errorf("unable to call Watch with wrapped client that does not implement client.WithWatch"))
+	}
+
+	gvr, namespace, name, err := w.objmeta(list)
+	if err != nil {
+		return nil, err
+	}
+
+	// call reactor chain
+	err = w.reactWatcherFunc(clientgotesting.NewGetAction(gvr, namespace, name))
+	if err != nil {
+		return nil, err
+	}
+	err = w.reactWatcherFunc(clientgotesting.NewCreateAction(gvr, namespace, list))
+	if err != nil {
+		return nil, err
+	}
+	err = w.reactWatcherFunc(clientgotesting.NewDeleteAction(gvr, namespace, name))
+	if err != nil {
+		return nil, err
+	}
+	err = w.reactWatcherFunc(clientgotesting.NewUpdateAction(gvr, namespace, list))
+	if err != nil {
+		return nil, err
+	}
+
+	if !duck.IsDuck(list, w.Scheme()) {
+		return ww.Watch(ctx, list, opts...)
+	}
+
+	uObj, err := runtime.DefaultUnstructuredConverter.ToUnstructured(list)
+	if err != nil {
+		return nil, err
+	}
+	u := &unstructured.UnstructuredList{Object: uObj}
+	watcher, err := ww.Watch(ctx, u, opts...)
+	if err != nil {
+		return nil, err
+	}
+	if err := runtime.DefaultUnstructuredConverter.FromUnstructured(u.Object, list); err != nil {
+		return nil, err
+	}
+	return watcher, nil
+}
+
 func (w *clientWrapper) Status() client.StatusWriter {
 	return &statusWriterWrapper{
 		statusWriter:  w.client.Status(),

testing/config.go

@@ -69,6 +69,9 @@ type ExpectConfig struct {
 	// WithReactors installs each ReactionFunc into each fake clientset. ReactionFuncs intercept
 	// each call to the clientset providing the ability to mutate the resource or inject an error.
 	WithReactors []ReactionFunc
+	// WithWatchReactors installs WatchReactionFunc into the fake clientset. This provides ability
+	// to simulate events in the watcher.
+	WithWatchReactors []WatchReactionFunc
 	// GivenTracks provide a set of tracked resources to seed the tracker with
 	GivenTracks []TrackRequest
 
@@ -119,6 +122,11 @@ func (c *ExpectConfig) init() {
 			reactor := c.WithReactors[len(c.WithReactors)-1-i]
 			c.client.PrependReactor("*", "*", reactor)
 		}
+		for i := range c.WithWatchReactors {
+			// in reverse order since we prepend
+			watchReactor := c.WithWatchReactors[len(c.WithWatchReactors)-1-i]
+			c.client.PrependWatchReactor("*", watchReactor)
+		}
 		c.apiReader = c.createClient(apiGivenObjects, c.StatusSubResourceTypes)
 		c.recorder = &eventRecorder{
 			events: []Event{},

testing/reconciler.go

@@ -48,9 +48,10 @@ type ReconcilerTestCase struct {
 
 	// Request identifies the object to be reconciled
 	Request reconcilers.Request
-	// WithReactors installs each ReactionFunc into each fake clientset. ReactionFuncs intercept
+	// WithReactors and WithWatchReactors installs each ReactionFunc into each fake clientset. ReactionFuncs intercept
 	// each call to the clientset providing the ability to mutate the resource or inject an error.
-	WithReactors []ReactionFunc
+	WithReactors      []ReactionFunc
+	WithWatchReactors []WatchReactionFunc
 	// WithClientBuilder allows a test to modify the fake client initialization.
 	WithClientBuilder func(*fake.ClientBuilder) *fake.ClientBuilder
 	// StatusSubResourceTypes is a set of object types that support the status sub-resource. For
@@ -188,6 +189,7 @@ func (tc *ReconcilerTestCase) Run(t *testing.T, scheme *runtime.Scheme, factory
 		APIGivenObjects:         tc.APIGivenObjects,
 		WithClientBuilder:       tc.WithClientBuilder,
 		WithReactors:            tc.WithReactors,
+		WithWatchReactors:       tc.WithWatchReactors,
 		GivenTracks:             tc.GivenTracks,
 		ExpectTracks:            tc.ExpectTracks,
 		ExpectEvents:            tc.ExpectEvents,

testing/subreconciler.go

@@ -56,9 +56,10 @@ type SubReconcilerTestCase[Type client.Object] struct {
 	GivenStashedValues map[reconcilers.StashKey]interface{}
 	// WithClientBuilder allows a test to modify the fake client initialization.
 	WithClientBuilder func(*fake.ClientBuilder) *fake.ClientBuilder
-	// WithReactors installs each ReactionFunc into each fake clientset. ReactionFuncs intercept
+	// WithReactors and WithWatchReactors installs each ReactionFunc into each fake clientset. ReactionFuncs intercept
 	// each call to the clientset providing the ability to mutate the resource or inject an error.
-	WithReactors []ReactionFunc
+	WithReactors      []ReactionFunc
+	WithWatchReactors []WatchReactionFunc
 	// StatusSubResourceTypes is a set of object types that support the status sub-resource. For
 	// these types, the only way to modify the resource's status is update or patch the status
 	// sub-resource. Patching or updating the main resource will not mutated the status field.
@@ -216,6 +217,7 @@ func (tc *SubReconcilerTestCase[T]) Run(t *testing.T, scheme *runtime.Scheme, fa
 		APIGivenObjects:         append(tc.APIGivenObjects, givenResource),
 		WithClientBuilder:       tc.WithClientBuilder,
 		WithReactors:            tc.WithReactors,
+		WithWatchReactors:       tc.WithWatchReactors,
 		GivenTracks:             tc.GivenTracks,
 		ExpectTracks:            tc.ExpectTracks,
 		ExpectEvents:            tc.ExpectEvents,

testing/webhook.go

@@ -54,9 +54,10 @@ type AdmissionWebhookTestCase struct {
 	HTTPRequest *http.Request
 	// WithClientBuilder allows a test to modify the fake client initialization.
 	WithClientBuilder func(*fake.ClientBuilder) *fake.ClientBuilder
-	// WithReactors installs each ReactionFunc into each fake clientset. ReactionFuncs intercept
+	// WithReactors and WithWatchReactors installs each ReactionFunc into each fake clientset. ReactionFuncs intercept
 	// each call to the clientset providing the ability to mutate the resource or inject an error.
-	WithReactors []ReactionFunc
+	WithReactors      []ReactionFunc
+	WithWatchReactors []WatchReactionFunc
 	// StatusSubResourceTypes is a set of object types that support the status sub-resource. For
 	// these types, the only way to modify the resource's status is update or patch the status
 	// sub-resource. Patching or updating the main resource will not mutated the status field.
@@ -181,6 +182,7 @@ func (tc *AdmissionWebhookTestCase) Run(t *testing.T, scheme *runtime.Scheme, fa
 		APIGivenObjects:         tc.APIGivenObjects,
 		WithClientBuilder:       tc.WithClientBuilder,
 		WithReactors:            tc.WithReactors,
+		WithWatchReactors:       tc.WithWatchReactors,
 		GivenTracks:             tc.GivenTracks,
 		ExpectTracks:            tc.ExpectTracks,
 		ExpectEvents:            tc.ExpectEvents,