add cluster-aware versions of gentype and listers

On-behalf-of: @SAP [email protected]

Author: xrstf

third_party/k8s.io/client-go/gentype/fake_cluster.go

@@ -0,0 +1,120 @@
+/*
+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 gentype
+
+import (
+	"context"
+
+	kcptesting "github.com/kcp-dev/client-go/third_party/k8s.io/client-go/testing"
+	"github.com/kcp-dev/logicalcluster/v3"
+
+	"k8s.io/apimachinery/pkg/api/meta"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	labels "k8s.io/apimachinery/pkg/labels"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	watch "k8s.io/apimachinery/pkg/watch"
+)
+
+// FakeClusterClient represents a fake cluster client
+type FakeClusterClient[T objectWithMeta] struct {
+	*kcptesting.Fake
+	resource  schema.GroupVersionResource
+	kind      schema.GroupVersionKind
+	newObject func() T
+}
+
+// FakeClusterClientWithList represents a fake cluster client with support for lists.
+type FakeClusterClientWithList[T objectWithMeta, L runtime.Object] struct {
+	*FakeClusterClient[T]
+	alsoFakeClusterLister[T, L]
+}
+
+// Helper types for composition
+type alsoFakeClusterLister[T objectWithMeta, L runtime.Object] struct {
+	client       *FakeClusterClient[T]
+	newList      func() L
+	copyListMeta func(L, L)
+	getItems     func(L) []T
+	setItems     func(L, []T)
+}
+
+// NewFakeClient constructs a fake client, namespaced or not, with no support for lists or apply.
+// Non-namespaced clients are constructed by passing an empty namespace ("").
+func NewFakeClusterClient[T objectWithMeta](
+	fake *kcptesting.Fake, resource schema.GroupVersionResource, kind schema.GroupVersionKind, emptyObjectCreator func() T,
+) *FakeClusterClient[T] {
+	return &FakeClusterClient[T]{fake, resource, kind, emptyObjectCreator}
+}
+
+// NewFakeClusterClientWithList constructs a namespaced client with support for lists.
+func NewFakeClusterClientWithList[T objectWithMeta, L runtime.Object](
+	fake *kcptesting.Fake, resource schema.GroupVersionResource, kind schema.GroupVersionKind, emptyObjectCreator func() T,
+	emptyListCreator func() L, listMetaCopier func(L, L), itemGetter func(L) []T, itemSetter func(L, []T),
+) *FakeClusterClientWithList[T, L] {
+	fakeClusterClient := NewFakeClusterClient[T](fake, resource, kind, emptyObjectCreator)
+	return &FakeClusterClientWithList[T, L]{
+		fakeClusterClient,
+		alsoFakeClusterLister[T, L]{fakeClusterClient, emptyListCreator, listMetaCopier, itemGetter, itemSetter},
+	}
+}
+
+// List takes label and field selectors, and returns the list of resources that match those selectors.
+func (l *alsoFakeClusterLister[T, L]) List(ctx context.Context, opts metav1.ListOptions) (result L, err error) {
+	emptyResult := l.newList()
+	obj, err := l.client.Fake.
+		Invokes(kcptesting.NewListAction(l.client.resource, l.client.kind, logicalcluster.Wildcard, metav1.NamespaceAll, opts), emptyResult)
+	if obj == nil {
+		return emptyResult, err
+	}
+
+	label, _, _ := kcptesting.ExtractFromListOptions(opts)
+	if label == nil {
+		// Everything matches
+		return obj.(L), nil
+	}
+	list := l.newList()
+	l.copyListMeta(list, obj.(L))
+	var items []T
+	for _, item := range l.getItems(obj.(L)) {
+		itemMeta, err := meta.Accessor(item)
+		if err != nil {
+			// No ObjectMeta, nothing can match
+			continue
+		}
+		if label.Matches(labels.Set(itemMeta.GetLabels())) {
+			items = append(items, item)
+		}
+	}
+	l.setItems(list, items)
+	return list, err
+}
+
+// Watch returns a watch.Interface that watches the requested resources.
+func (c *FakeClusterClient[T]) Watch(ctx context.Context, opts metav1.ListOptions) (watch.Interface, error) {
+	opts.Watch = true
+	return c.Fake.
+		InvokesWatch(kcptesting.NewWatchAction(c.resource, logicalcluster.Wildcard, metav1.NamespaceAll, opts))
+}
+
+func (c *FakeClusterClient[T]) Kind() schema.GroupVersionKind {
+	return c.kind
+}
+
+func (c *FakeClusterClient[T]) Resource() schema.GroupVersionResource {
+	return c.resource
+}