Merge pull request #63330 from deads2k/api-13-sparse

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

add test for sparse version encoding/decoding

This adds tests that make sure the sparse version encoding and encoding work as callers will expect, with the correct version being picked from the list.  I wrote two tests, one a theoretical test not dependent on any API and another practical test using cronjobs which are currently sparse in the registry.

@liggitt turns out that because we find exact matches, sparse versions ought to work out fine.
@smarterclayton I hate that the versioner matches on type.  I'll update that separately I think.


```release-note
NONE
```

pkg/kubectl/scheme/BUILD

@@ -1,4 +1,4 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_library")
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
 
 go_library(
     name = "go_default_library",
@@ -61,3 +61,17 @@ filegroup(
     tags = ["automanaged"],
     visibility = ["//visibility:public"],
 )
+
+go_test(
+    name = "go_default_test",
+    srcs = ["sparse_test.go"],
+    embed = [":go_default_library"],
+    deps = [
+        "//vendor/k8s.io/api/batch/v1:go_default_library",
+        "//vendor/k8s.io/api/batch/v1beta1:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/api/equality:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/runtime:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/util/diff:go_default_library",
+    ],
+)

pkg/kubectl/scheme/sparse_test.go

@@ -0,0 +1,54 @@
+/*
+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 scheme
+
+import (
+	"testing"
+
+	"k8s.io/api/batch/v1"
+	"k8s.io/api/batch/v1beta1"
+	"k8s.io/apimachinery/pkg/api/equality"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/util/diff"
+)
+
+func TestCronJob(t *testing.T) {
+	src := &v1beta1.CronJob{ObjectMeta: metav1.ObjectMeta{Name: "foo"}}
+
+	encoder := Codecs.LegacyCodec(v1.SchemeGroupVersion, v1beta1.SchemeGroupVersion)
+	cronjobBytes, err := runtime.Encode(encoder, src)
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Log(string(cronjobBytes))
+	t.Log(Registry.RegisteredGroupVersions())
+
+	decoder := Codecs.UniversalDecoder(Registry.RegisteredGroupVersions()...)
+
+	uncastDst, err := runtime.Decode(decoder, cronjobBytes)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// clear typemeta
+	uncastDst.(*v1beta1.CronJob).TypeMeta = metav1.TypeMeta{}
+
+	if !equality.Semantic.DeepEqual(src, uncastDst) {
+		t.Fatal(diff.ObjectDiff(src, uncastDst))
+	}
+}