Add side input for golden file tests

Adds a posibility to provide a *.side_in.yaml file, that contains
resources that should exist before the resource defined in `*.in.yaml` is applied.
These side input resources are going to be created before running a testcase, and
cleaned up at the end of it. The resources will be accessible via Get and List.
Note that the existing functionality has not been changed.

docs/addon/walkthrough/tests.md

@@ -22,6 +22,11 @@ The bulk of these tests are implemented in `pkg/tests` via the `StandardValidato
 The test scans a `tests` directory for `*.in.yaml` files, runs the operator for each 
 of them, and compares the output to `*.out.yaml` files.
 
+It is also possible to provide `*.side_in.yaml` file that contains resources that
+should exist before the resource defined in `*.in.yaml` is applied. These resources
+are going to be created before running a test, and cleaned up upon finishing. They
+will be accessible via Get and List.
+
 We perform simple comparison-of-output tests, any changes
 to the output are treated as test failures, and printed as a diff. 
 This means that the output is materialized and checked in to the repo; this
@@ -59,7 +64,7 @@ the env-var cheat code.
     func TestController(t *testing.T) {
 	v := golden.NewValidator(t, api.SchemeBuilder)
 	dr := &{{operator}}Reconciler{
-		Client: v.Manager().GetClient(),
+		Client: v.Client(),
 	}
 	err := dr.setupReconciler(v.Manager())
 	if err != nil {

examples/guestbook-operator/controllers/guestbook_controller_test.go

@@ -27,7 +27,7 @@ import (
 func TestGuestbook(t *testing.T) {
 	v := golden.NewValidator(t, api.SchemeBuilder)
 	dr := &GuestbookReconciler{
-		Client: v.Manager().GetClient(),
+		Client: v.Client(),
 	}
 	err := dr.setupReconciler(v.Manager())
 	if err != nil {

pkg/test/golden/validator.go

@@ -32,7 +32,6 @@ import (
 	"k8s.io/apimachinery/pkg/runtime/serializer/json"
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/apimachinery/pkg/util/diff"
-	clientScheme "k8s.io/client-go/kubernetes/scheme"
 	"sigs.k8s.io/controller-runtime/pkg/scheme"
 	"sigs.k8s.io/kubebuilder-declarative-pattern/pkg/patterns/addon"
 	"sigs.k8s.io/kubebuilder-declarative-pattern/pkg/patterns/addon/pkg/loaders"
@@ -52,7 +51,8 @@ func NewValidator(t *testing.T, b *scheme.Builder) *validator {
 	addon.Init()
 	v.findChannelsPath()
 
-	v.mgr = mocks.NewManager(mocks.NewClient(clientScheme.Scheme))
+	v.client = mocks.NewClient(v.scheme)
+	v.mgr = mocks.NewManager(v.client)
 	v.mgr.Scheme = v.scheme
 	return v
 }
@@ -62,6 +62,7 @@ type validator struct {
 	scheme  *runtime.Scheme
 	TestDir string
 	mgr     mocks.Manager
+	client  mocks.FakeClient
 }
 
 // findChannelsPath will search for a channels directory, which is helpful when running under bazel
@@ -132,6 +133,10 @@ func (v *validator) Manager() *mocks.Manager {
 	return &v.mgr
 }
 
+func (v *validator) Client() *mocks.FakeClient {
+	return &v.client
+}
+
 func (v *validator) Validate(r declarative.Reconciler) {
 	t := v.T
 	t.Helper()
@@ -168,13 +173,41 @@ func (v *validator) Validate(r declarative.Reconciler) {
 			continue
 		}
 
+		// Ignore any files that are not input - we want to find .side_in and .out files
+		// that correspond to given .in file
 		if !strings.HasSuffix(p, ".in.yaml") {
-			if !strings.HasSuffix(p, ".out.yaml") {
-				t.Errorf("unexpected file in tests directory: %s", p)
-			}
 			continue
 		}
 
+		objectsToCleanup := []runtime.Object{}
+		// Check if there is a file containing side inputs for this test
+		sideInputPath := strings.Replace(p, ".in.yaml", ".side_in.yaml", -1)
+		sideInputRead, err := os.ReadFile(sideInputPath)
+		if err != nil {
+			t.Logf("Could not read side input file %s: %v, skipping", sideInputPath, err)
+		} else {
+			objs, err := manifest.ParseObjects(ctx, string(sideInputRead))
+			if err != nil {
+				t.Errorf("error parsing file %s: %v", p, err)
+				continue
+			}
+
+			for _, obj := range objs.Items {
+				json, err := obj.JSON()
+				if err != nil {
+					t.Errorf("error converting resource to json in %s: %v", p, err)
+					continue
+				}
+				decoded, _, err := serializer.Decode(json, nil, nil)
+				if err != nil {
+					t.Errorf("error parsing resource in %s: %v", p, err)
+					continue
+				}
+				v.client.CreateRuntimeObject(ctx, decoded)
+				objectsToCleanup = append(objectsToCleanup, decoded)
+			}
+		}
+
 		b, err := os.ReadFile(p)
 		if err != nil {
 			t.Errorf("error reading file %s: %v", p, err)
@@ -273,6 +306,10 @@ func (v *validator) Validate(r declarative.Reconciler) {
 			t.Logf(`To regenerate the output based on this result, rerun this test with HACK_AUTOFIX_EXPECTED_OUTPUT="true"`)
 		}
 
+		for _, objectToCleanup := range objectsToCleanup {
+			v.client.DeleteRuntimeObject(ctx, objectToCleanup)
+		}
+
 	}
 }
 

pkg/test/mocks/client.go

@@ -46,11 +46,44 @@ func (f FakeClient) Get(ctx context.Context, key client.ObjectKey, out client.Ob
 	return err
 }
 
-func (FakeClient) List(ctx context.Context, list client.ObjectList, opts ...client.ListOption) error {
-	panic("not implemented")
+func (f FakeClient) List(ctx context.Context, list client.ObjectList, opts ...client.ListOption) error {
+	gvkUnprocessed, err := apiutil.GVKForObject(list, f.scheme)
+	if err != nil {
+		return err
+	}
+	// this will be a SomethingList kind, and we want to get the Something: remove `List` (last 4 chars) of this string
+	nonListKind := gvkUnprocessed.Kind
+	nonListKind = nonListKind[:len(nonListKind)-4]
+	gvk := schema.GroupVersionKind{gvkUnprocessed.Group, gvkUnprocessed.Version, nonListKind}
+	gvr, _ := meta.UnsafeGuessKindToResource(gvk)
+
+	listObject, err := f.tracker.List(gvr, gvk, "")
+	if err != nil {
+		return err
+	}
+
+	items, err := meta.ExtractList(listObject)
+	if err != nil {
+		return err
+	}
+
+	return meta.SetList(list, items)
 }
 
 func (f FakeClient) Create(ctx context.Context, obj client.Object, opts ...client.CreateOption) error {
+	gvr, err := getGVRFromObject(obj, f.scheme)
+	if err != nil {
+		return err
+	}
+	return f.create(gvr, obj, opts...)
+}
+
+func (f FakeClient) CreateRuntimeObject(ctx context.Context, obj runtime.Object, opts ...client.CreateOption) error {
+	gvr := getGVRFromRuntimeObject(obj)
+	return f.create(gvr, obj, opts...)
+}
+
+func (f FakeClient) create(gvr schema.GroupVersionResource, obj runtime.Object, opts ...client.CreateOption) error {
 	createOptions := &client.CreateOptions{}
 	createOptions.ApplyOptions(opts)
 
@@ -60,19 +93,28 @@ func (f FakeClient) Create(ctx context.Context, obj client.Object, opts ...clien
 		}
 	}
 
-	gvr, err := getGVRFromObject(obj, f.scheme)
+	accessor, err := meta.Accessor(obj)
 	if err != nil {
 		return err
 	}
-	accessor, err := meta.Accessor(obj)
+	return f.tracker.Create(gvr, obj, accessor.GetNamespace())
+}
+
+func (f FakeClient) Delete(ctx context.Context, obj client.Object, opts ...client.DeleteOption) error {
+	gvr, err := getGVRFromObject(obj, f.scheme)
 	if err != nil {
 		return err
 	}
-	return f.tracker.Create(gvr, obj, accessor.GetNamespace())
+	return f.tracker.Delete(gvr, obj.GetNamespace(), obj.GetName())
 }
 
-func (FakeClient) Delete(ctx context.Context, obj client.Object, opts ...client.DeleteOption) error {
-	return nil
+func (f FakeClient) DeleteRuntimeObject(ctx context.Context, obj runtime.Object, opts ...client.DeleteOption) error {
+	gvr := getGVRFromRuntimeObject(obj)
+	accessor, err := meta.Accessor(obj)
+	if err != nil {
+		return err
+	}
+	return f.tracker.Delete(gvr, accessor.GetNamespace(), accessor.GetName())
 }
 
 func (FakeClient) DeleteAllOf(ctx context.Context, obj client.Object, opts ...client.DeleteAllOfOption) error {
@@ -108,6 +150,12 @@ func getGVRFromObject(obj client.Object, scheme *runtime.Scheme) (schema.GroupVe
 	return gvr, nil
 }
 
+func getGVRFromRuntimeObject(obj runtime.Object) schema.GroupVersionResource {
+	gvk := obj.GetObjectKind().GroupVersionKind()
+	gvr, _ := meta.UnsafeGuessKindToResource(gvk)
+	return gvr
+}
+
 type FakeStatusClient struct{}
 
 func (FakeStatusClient) Update(ctx context.Context, obj client.Object, opts ...client.UpdateOption) error {