Test for type-level preserve-unknown-fields

This adds a test for type-level `pruning:PreserveUnknownFields` to the
crd test.

pkg/crd/testdata/cronjob_types.go

@@ -23,6 +23,7 @@ limitations under the License.
 package cronjob
 
 import (
+	"encoding/json"
 	"fmt"
 
 	batchv1beta1 "k8s.io/api/batch/v1beta1"
@@ -127,6 +128,9 @@ type CronJobSpec struct {
 	// +kubebuilder:validation:nullable
 	UnprunedEmbeddedResource runtime.RawExtension `json:"unprunedEmbeddedResource"`
 
+	// This tests that a type-level pruning maker works.
+	UnprunedFromType Preserved `json:"unprunedFomType"`
+
 	// This tests that associative lists work.
 	// +listType=map
 	// +listMapKey=name
@@ -142,6 +146,37 @@ type CronJobSpec struct {
 	StructWithSeveralFields NestedObject `json:"structWithSeveralFields"`
 }
 
+// +kubebuilder:validation:Type=object
+// +kubebuilder:pruning:PreserveUnknownFields
+type Preserved struct {
+	ConcreteField string `json:"concreteField"`
+	Rest map[string]interface{} `json:"-"`
+}
+func (p *Preserved) UnmarshalJSON(data []byte) error {
+	if err := json.Unmarshal(data, &p.Rest); err != nil {
+		return err
+	}
+	conc, found := p.Rest["concreteField"]
+	if !found {
+		return nil
+	}
+	concStr, isStr := conc.(string)
+	if !isStr {
+		return fmt.Errorf("concreteField was not string")
+	}
+	delete(p.Rest, "concreteField")
+	p.ConcreteField = concStr
+	return nil
+}
+func (p *Preserved) MarshalJSON() ([]byte, error) {
+	full := make(map[string]interface{}, len(p.Rest)+1)
+	for k, v := range p.Rest {
+		full[k] = v
+	}
+	full["concreteField"] = p.ConcreteField
+	return json.Marshal(full)
+}
+
 type NestedObject struct {
 	Foo string `json:"foo"`
 	Bar bool   `json:"bar"`

pkg/crd/testdata/testdata.kubebuilder.io_cronjobs.yaml

@@ -5090,6 +5090,15 @@ spec:
                 type: object
                 x-kubernetes-embedded-resource: true
                 x-kubernetes-preserve-unknown-fields: true
+              unprunedFomType:
+                description: This tests that a type-level pruning maker works.
+                properties:
+                  concreteField:
+                    type: string
+                required:
+                - concreteField
+                type: object
+                x-kubernetes-preserve-unknown-fields: true
               unprunedJSON:
                 properties:
                   bar:
@@ -5117,6 +5126,7 @@ spec:
             - twoOfAKindPart0
             - twoOfAKindPart1
             - unprunedEmbeddedResource
+            - unprunedFomType
             - unprunedJSON
             type: object
           status: