Add unit tests for utils packages (#482)

* Drop `client.DeduplicateWarnings` in favor of controller-runtime

`client.New` configures `logf.NewKubeAPIWarningLogger` on the client by default.

* Add unit tests for `pkg/utils`

* Add unit tests for `pkg/utils/client`

* Add unit tests for `pkg/utils/errors`

* Add unit tests for `pkg/utils/healthz`

* Drop custom `komega` package

Using the upstream `komega` package should be good enough for our purposes.
While using a global `context.Background` doesn't integrate nicely with ginkgo/gomega's
context handling. However, we expect client calls to return fast enough in test that
this doesn't really matter.

* Fix `EachListItemWithAlloc` and use it

* Add unit tests for `pkg/utils/pager`

Author: timebertt

cmd/sharder/main.go

@@ -23,12 +23,9 @@ import (
 	"sigs.k8s.io/controller-runtime/pkg/manager/signals"
 
 	"github.com/timebertt/kubernetes-controller-sharding/cmd/sharder/app"
-	"github.com/timebertt/kubernetes-controller-sharding/pkg/utils/client"
 )
 
 func main() {
-	client.DeduplicateWarnings()
-
 	if err := app.NewCommand().ExecuteContext(signals.SetupSignalHandler()); err != nil {
 		fmt.Println(err)
 		os.Exit(1)

go.mod

@@ -7,7 +7,6 @@ toolchain go1.24.0
 require (
 	github.com/cespare/xxhash/v2 v2.3.0
 	github.com/go-logr/logr v1.4.2
-	github.com/google/go-cmp v0.6.0
 	github.com/google/uuid v1.6.0
 	github.com/hashicorp/go-multierror v1.1.1
 	github.com/onsi/ginkgo/v2 v2.22.2
@@ -54,6 +53,7 @@ require (
 	github.com/google/btree v1.1.3 // indirect
 	github.com/google/cel-go v0.22.0 // indirect
 	github.com/google/gnostic-models v0.6.8 // indirect
+	github.com/google/go-cmp v0.6.0 // indirect
 	github.com/google/gofuzz v1.2.0 // indirect
 	github.com/google/pprof v0.0.0-20241210010833-40e02aabc2ad // indirect
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.20.0 // indirect

pkg/controller/sharder/reconciler.go

@@ -166,7 +166,7 @@ func (r *Reconciler) resyncResource(
 
 	list := &metav1.PartialObjectMetadataList{}
 	list.SetGroupVersionKind(gvks[0])
-	err = pager.New(r.Reader).EachListItem(ctx, list,
+	err = pager.New(r.Reader).EachListItemWithAlloc(ctx, list,
 		func(obj client.Object) error {
 			if !namespaces.Has(obj.GetNamespace()) {
 				return nil

pkg/utils/client/warnings.go renamed to pkg/utils/client/client_suite_test.go

@@ -1,5 +1,5 @@
 /*
-Copyright 2023 Tim Ebert.
+Copyright 2025 Tim Ebert.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -14,20 +14,16 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-package client
+package client_test
 
 import (
-	"os"
+	"testing"
 
-	"k8s.io/client-go/rest"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
 )
 
-// DeduplicateWarnings configures a client-go warning handler that deduplicates API warnings in order to not spam logs.
-func DeduplicateWarnings() {
-	rest.SetDefaultWarningHandler(
-		rest.NewWarningWriter(os.Stderr, rest.WarningWriterOptions{
-			// only print a given warning the first time we receive it
-			Deduplicate: true,
-		}),
-	)
+func TestClient(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Client Utils Suite")
 }

pkg/utils/client/options_test.go

@@ -0,0 +1,41 @@
+/*
+Copyright 2025 Tim Ebert.
+
+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 client_test
+
+import (
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+
+	. "github.com/timebertt/kubernetes-controller-sharding/pkg/utils/client"
+)
+
+var _ = Describe("ResourceVersion", func() {
+	It("should set the resourceVersion on GetOptions", func() {
+		opts := &client.GetOptions{}
+		opts.ApplyOptions([]client.GetOption{ResourceVersion("1")})
+
+		Expect(opts.Raw.ResourceVersion).To(Equal("1"))
+	})
+
+	It("should set the resourceVersion on ListOptions", func() {
+		opts := &client.ListOptions{}
+		opts.ApplyOptions([]client.ListOption{ResourceVersion("1")})
+
+		Expect(opts.Raw.ResourceVersion).To(Equal("1"))
+	})
+})

pkg/utils/test/komega/doc.go renamed to pkg/utils/errors/errors_suite_test.go

@@ -1,5 +1,5 @@
 /*
-Copyright 2024 Tim Ebert.
+Copyright 2025 Tim Ebert.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -14,12 +14,16 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-// Package komega is a modified version of sigs.k8s.io/controller-runtime/pkg/envtest/komega.
-// Instead of requiring users to set a global context, the returned functions accept a context to integrate nicely with
-// ginkgo's/gomega's timeout/interrupt handling and polling.
-// For this, users must pass a spec-specific context, e.g.:
-//
-//	It("...", func(ctx SpecContext) {
-//		Eventually(ctx, Get(...)).Should(Succeed())
-//	})
-package komega
+package errors_test
+
+import (
+	"testing"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+func TestErrors(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Errors Utils Suite")
+}

pkg/utils/errors/multi.go

@@ -22,7 +22,7 @@ import (
 )
 
 // FormatErrors is like multierror.ListFormatFunc without the noisy newlines and tabs.
-// It also simplies the format for a single error.
+// It also simplifies the format for a single error.
 func FormatErrors(es []error) string {
 	if len(es) == 1 {
 		return es[0].Error()

pkg/utils/errors/multi_test.go

@@ -0,0 +1,40 @@
+/*
+Copyright 2025 Tim Ebert.
+
+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 errors_test
+
+import (
+	"fmt"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+
+	. "github.com/timebertt/kubernetes-controller-sharding/pkg/utils/errors"
+)
+
+var _ = Describe("FormatErrors", func() {
+	It("should return the single error", func() {
+		Expect(FormatErrors([]error{fmt.Errorf("foo")})).To(Equal("foo"))
+	})
+
+	It("should return the error count and comma separated error list", func() {
+		Expect(
+			FormatErrors([]error{fmt.Errorf("foo"), fmt.Errorf("bar")}),
+		).To(
+			Equal("2 errors occurred: foo, bar"),
+		)
+	})
+})

pkg/utils/healthz/cache_test.go

@@ -0,0 +1,43 @@
+/*
+Copyright 2025 Tim Ebert.
+
+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 healthz_test
+
+import (
+	"context"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+
+	. "github.com/timebertt/kubernetes-controller-sharding/pkg/utils/healthz"
+)
+
+var _ = Describe("CacheSync", func() {
+	It("should succeed if all informers sync", func() {
+		checker := CacheSync(fakeSyncWaiter(true))
+		Expect(checker(nil)).NotTo(HaveOccurred())
+	})
+	It("should fail if informers don't sync", func() {
+		checker := CacheSync(fakeSyncWaiter(false))
+		Expect(checker(nil)).To(MatchError(ContainSubstring("not synced")))
+	})
+})
+
+type fakeSyncWaiter bool
+
+func (f fakeSyncWaiter) WaitForCacheSync(_ context.Context) bool {
+	return bool(f)
+}

pkg/utils/healthz/healthz_suite_test.go

@@ -0,0 +1,29 @@
+/*
+Copyright 2025 Tim Ebert.
+
+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 healthz_test
+
+import (
+	"testing"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+func TestHealthz(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Healthz Suite")
+}