✨ fakeclient: Add support for ServiceAccount Token subresource (kubernetes-sigs#2969)

* fake: Add ServiceAccount Token subresource

* go fmt

* add tests

* go fmt

* correct wrong type test

Author: glennpratt

pkg/client/fake/client.go

@@ -32,6 +32,7 @@ import (
 	// Using v4 to match upstream
 	jsonpatch "gopkg.in/evanphx/json-patch.v4"
 	appsv1 "k8s.io/api/apps/v1"
+	authenticationv1 "k8s.io/api/authentication/v1"
 	autoscalingv1 "k8s.io/api/autoscaling/v1"
 	corev1 "k8s.io/api/core/v1"
 	policyv1 "k8s.io/api/policy/v1"
@@ -1128,7 +1129,7 @@ func (sw *fakeSubResourceClient) Get(ctx context.Context, obj, subResource clien
 		}
 		scale, isScale := subResource.(*autoscalingv1.Scale)
 		if !isScale {
-			return apierrors.NewBadRequest(fmt.Sprintf("expected Scale, got %t", subResource))
+			return apierrors.NewBadRequest(fmt.Sprintf("expected Scale, got %T", subResource))
 		}
 		scaleOut, err := extractScale(obj)
 		if err != nil {
@@ -1149,13 +1150,26 @@ func (sw *fakeSubResourceClient) Create(ctx context.Context, obj client.Object,
 			_, isEviction = subResource.(*policyv1.Eviction)
 		}
 		if !isEviction {
-			return apierrors.NewBadRequest(fmt.Sprintf("got invalid type %t, expected Eviction", subResource))
+			return apierrors.NewBadRequest(fmt.Sprintf("got invalid type %T, expected Eviction", subResource))
 		}
 		if _, isPod := obj.(*corev1.Pod); !isPod {
 			return apierrors.NewNotFound(schema.GroupResource{}, "")
 		}
 
 		return sw.client.Delete(ctx, obj)
+	case "token":
+		tokenRequest, isTokenRequest := subResource.(*authenticationv1.TokenRequest)
+		if !isTokenRequest {
+			return apierrors.NewBadRequest(fmt.Sprintf("got invalid type %T, expected TokenRequest", subResource))
+		}
+		if _, isServiceAccount := obj.(*corev1.ServiceAccount); !isServiceAccount {
+			return apierrors.NewNotFound(schema.GroupResource{}, "")
+		}
+
+		tokenRequest.Status.Token = "fake-token"
+		tokenRequest.Status.ExpirationTimestamp = metav1.Date(6041, 1, 1, 0, 0, 0, 0, time.UTC)
+
+		return sw.client.Get(ctx, client.ObjectKeyFromObject(obj), obj)
 	default:
 		return fmt.Errorf("fakeSubResourceWriter does not support create for %s", sw.subResource)
 	}
@@ -1176,7 +1190,7 @@ func (sw *fakeSubResourceClient) Update(ctx context.Context, obj client.Object,
 
 		scale, isScale := updateOptions.SubResourceBody.(*autoscalingv1.Scale)
 		if !isScale {
-			return apierrors.NewBadRequest(fmt.Sprintf("expected Scale, got %t", updateOptions.SubResourceBody))
+			return apierrors.NewBadRequest(fmt.Sprintf("expected Scale, got %T", updateOptions.SubResourceBody))
 		}
 		if err := applyScale(obj, scale); err != nil {
 			return err

pkg/client/fake/client_test.go

@@ -27,6 +27,7 @@ import (
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
 	appsv1 "k8s.io/api/apps/v1"
+	authenticationv1 "k8s.io/api/authentication/v1"
 	autoscalingv1 "k8s.io/api/autoscaling/v1"
 	coordinationv1 "k8s.io/api/coordination/v1"
 	corev1 "k8s.io/api/core/v1"
@@ -1959,6 +1960,41 @@ var _ = Describe("Fake client", func() {
 		Expect(apierrors.IsBadRequest(err)).To(BeTrue())
 	})
 
+	It("should create a ServiceAccount token through the token subresource", func() {
+		sa := &corev1.ServiceAccount{ObjectMeta: metav1.ObjectMeta{Name: "foo"}}
+		cl := NewClientBuilder().WithObjects(sa).Build()
+
+		tokenRequest := &authenticationv1.TokenRequest{}
+		err := cl.SubResource("token").Create(context.Background(), sa, tokenRequest)
+		Expect(err).NotTo(HaveOccurred())
+
+		Expect(tokenRequest.Status.Token).NotTo(Equal(""))
+		Expect(tokenRequest.Status.ExpirationTimestamp).NotTo(Equal(metav1.Time{}))
+	})
+
+	It("should return not found when creating a token for a ServiceAccount that doesn't exist", func() {
+		sa := &corev1.ServiceAccount{ObjectMeta: metav1.ObjectMeta{Name: "foo"}}
+		cl := NewClientBuilder().Build()
+
+		err := cl.SubResource("token").Create(context.Background(), sa, &authenticationv1.TokenRequest{})
+		Expect(err).To(HaveOccurred())
+		Expect(apierrors.IsNotFound(err)).To(BeTrue())
+	})
+
+	It("should error when creating a token with the wrong subresource type", func() {
+		cl := NewClientBuilder().Build()
+		err := cl.SubResource("token").Create(context.Background(), &corev1.ServiceAccount{}, &corev1.Namespace{})
+		Expect(err).To(HaveOccurred())
+		Expect(apierrors.IsBadRequest(err)).To(BeTrue())
+	})
+
+	It("should error when creating a token with the wrong type", func() {
+		cl := NewClientBuilder().Build()
+		err := cl.SubResource("token").Create(context.Background(), &corev1.Secret{}, &authenticationv1.TokenRequest{})
+		Expect(err).To(HaveOccurred())
+		Expect(apierrors.IsNotFound(err)).To(BeTrue())
+	})
+
 	It("should leave typemeta empty on typed get", func() {
 		cl := NewClientBuilder().WithObjects(&corev1.Pod{ObjectMeta: metav1.ObjectMeta{
 			Namespace: "default",