Add missing imports in register-gen

Due to a recent change in k8s.io/gengo/v2, the register-gen is
missing 2 imports.The imports were previously auto inserted during
the code generation by k8s.io/gengo/v2.
Now, instead, they are directly imported by the register-gen.

An output_tests has been added to register-gen. This generates an
example, which would have been invalid with these changes.

Signed-off-by: Lionel Jouin <[email protected]>

Author: LionelJouin

staging/src/k8s.io/code-generator/cmd/register-gen/generators/register_external.go

@@ -61,11 +61,15 @@ func (g *registerExternalGenerator) Finalize(context *generator.Context, w io.Wr
 
 	sw := generator.NewSnippetWriter(w, context, "$", "$")
 	m := map[string]interface{}{
-		"groupName":         g.gv.Group,
-		"version":           g.gv.Version,
-		"types":             typesToGenerateOnlyNames,
-		"addToGroupVersion": context.Universe.Function(types.Name{Package: "k8s.io/apimachinery/pkg/apis/meta/v1", Name: "AddToGroupVersion"}),
-		"groupVersion":      context.Universe.Type(types.Name{Package: "k8s.io/apimachinery/pkg/apis/meta/v1", Name: "GroupVersion"}),
+		"groupName":           g.gv.Group,
+		"version":             g.gv.Version,
+		"types":               typesToGenerateOnlyNames,
+		"addToGroupVersion":   context.Universe.Function(types.Name{Package: "k8s.io/apimachinery/pkg/apis/meta/v1", Name: "AddToGroupVersion"}),
+		"groupVersion":        context.Universe.Type(types.Name{Package: "k8s.io/apimachinery/pkg/apis/meta/v1", Name: "GroupVersion"}),
+		"schemaGroupVersion":  context.Universe.Type(types.Name{Package: "k8s.io/apimachinery/pkg/runtime/schema", Name: "GroupVersion"}),
+		"schemaGroupResource": context.Universe.Type(types.Name{Package: "k8s.io/apimachinery/pkg/runtime/schema", Name: "GroupResource"}),
+		"scheme":              context.Universe.Type(types.Name{Package: "k8s.io/apimachinery/pkg/runtime", Name: "Scheme"}),
+		"schemeBuilder":       context.Universe.Type(types.Name{Package: "k8s.io/apimachinery/pkg/runtime", Name: "SchemeBuilder"}),
 	}
 	sw.Do(registerExternalTypesTemplate, m)
 	return sw.Error()
@@ -80,16 +84,16 @@ var GroupVersion = $.groupVersion|raw${Group: GroupName, Version: "$.version$"}
 
 // SchemeGroupVersion is group version used to register these objects
 // Deprecated: use GroupVersion instead.
-var SchemeGroupVersion = schema.GroupVersion{Group: GroupName, Version: "$.version$"}
+var SchemeGroupVersion = $.schemaGroupVersion|raw${Group: GroupName, Version: "$.version$"}
 
 // Resource takes an unqualified resource and returns a Group qualified GroupResource
-func Resource(resource string) schema.GroupResource {
+func Resource(resource string) $.schemaGroupResource|raw$ {
 	return SchemeGroupVersion.WithResource(resource).GroupResource()
 }
 
 var (
 	// localSchemeBuilder and AddToScheme will stay in k8s.io/kubernetes.
-	SchemeBuilder      runtime.SchemeBuilder
+	SchemeBuilder      $.schemeBuilder|raw$
 	localSchemeBuilder = &SchemeBuilder
     // Deprecated: use Install instead
 	AddToScheme        = localSchemeBuilder.AddToScheme
@@ -104,7 +108,7 @@ func init() {
 }
 
 // Adds the list of known types to Scheme.
-func addKnownTypes(scheme *runtime.Scheme) error {
+func addKnownTypes(scheme *$.scheme|raw$) error {
 	scheme.AddKnownTypes(SchemeGroupVersion,
     $range .types -$
         &$.${},

staging/src/k8s.io/code-generator/cmd/register-gen/output_tests/generate.go

@@ -0,0 +1,20 @@
+//go:build !ignore_autogenerated
+
+/*
+Copyright 2024 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+//go:generate go run k8s.io/code-generator/cmd/register-gen --output-file zz_generated.register.go --go-header-file=../../../examples/hack/boilerplate.go.txt k8s.io/code-generator/cmd/register-gen/output_tests/...
+package outputtests

staging/src/k8s.io/code-generator/cmd/register-gen/output_tests/simpletype/doc.go

@@ -0,0 +1,18 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// +groupName=simpletype.foo.bar
+package simpletype

staging/src/k8s.io/code-generator/cmd/register-gen/output_tests/simpletype/fake_deepcopy.go

@@ -0,0 +1,44 @@
+/*
+Copyright 2024 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package simpletype
+
+import (
+	"k8s.io/apimachinery/pkg/runtime"
+)
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *SimpleType) DeepCopyInto(out *SimpleType) {
+	*out = *in
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new Inner.
+func (in *SimpleType) DeepCopy() *SimpleType {
+	if in == nil {
+		return nil
+	}
+	out := new(SimpleType)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyObject is an autogenerated deepcopy function, copying the receiver, creating a new runtime.Object.
+func (in *SimpleType) DeepCopyObject() runtime.Object {
+	if c := in.DeepCopy(); c != nil {
+		return c
+	}
+	return nil
+}

staging/src/k8s.io/code-generator/cmd/register-gen/output_tests/simpletype/types.go

@@ -0,0 +1,25 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package simpletype
+
+import (
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+type SimpleType struct {
+	metav1.TypeMeta `json:",inline"`
+}

staging/src/k8s.io/code-generator/cmd/register-gen/output_tests/simpletype/zz_generated.register.go

@@ -36,11 +36,14 @@ require (
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	github.com/x448/float16 v0.8.4 // indirect
 	golang.org/x/mod v0.21.0 // indirect
+	golang.org/x/net v0.30.0 // indirect
 	golang.org/x/sync v0.10.0 // indirect
 	golang.org/x/sys v0.28.0 // indirect
 	golang.org/x/tools v0.26.0 // indirect
 	google.golang.org/protobuf v1.35.1 // indirect
+	gopkg.in/inf.v0 v0.9.1 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
+	k8s.io/utils v0.0.0-20241104100929-3ea5e8cea738 // indirect
 	sigs.k8s.io/json v0.0.0-20241010143419-9aa6b5e7a4b3 // indirect
 	sigs.k8s.io/structured-merge-diff/v4 v4.4.2 // indirect
 )