},
			},
		},
	}
	for _, tc := range testCases {
		t.Run(tc.name, func(t *testing.T) {
			featuregatetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, apiextensionsfeatures.CRDValidationRatcheting, tc.enableRatcheting)
			featuregatetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, apiextensionsfeatures.CustomResourceFieldSelectors, tc.enableSelectableFields)
			old := tc.oldCRD.DeepCopy()

	// documentation for Optional types for more information:
	// https://pkg.go.dev/github.com/google/cel-go/cel#OptionalTypes
	//
	// May not be set unless `oldSelf` is used in `rule`.
	//
	// +featureGate=CRDValidationRatcheting
	// +optional
	OptionalOldSelf *bool `json:"optionalOldSelf,omitempty" protobuf:"bytes,6,opt,name=optionalOldSelf"`
}

// JSON represents any valid JSON value.

	// documentation for Optional types for more information:
	// https://pkg.go.dev/github.com/google/cel-go/cel#OptionalTypes
	//
	// May not be set unless `oldSelf` is used in `rule`.
	//
	// +featureGate=CRDValidationRatcheting
	// +optional
	OptionalOldSelf *bool `json:"optionalOldSelf,omitempty" protobuf:"bytes,6,opt,name=optionalOldSelf"`
}

// JSON represents any valid JSON value.

			// But if the rule uses optional oldSelf and gate is enabled we allow
			// the rule to be evaluated
			if !utilfeature.DefaultFeatureGate.Enabled(features.CRDValidationRatcheting) {
				continue
			}

			if !optionalOldSelfRule {
				continue
			}
		}

		ruleActivation := activation
		if optionalOldSelfRule {
			ruleActivation = optionalOldSelfActivation

	}
	return "is not a transition rule"
}

func TestCelCompilation(t *testing.T) {
	featuregatetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, apiextensionsfeatures.CRDValidationRatcheting, true)
	cases := []struct {
		name            string
		input           schema.Structural
		expectedResults []validationMatcher
		unmodified      bool
	}{
		{

	// inherited features from apiextensions-apiserver, relisted here to get a conflict if it is changed
	// unintentionally on either side:

	apiextensionsfeatures.CRDValidationRatcheting: {Default: true, PreRelease: featuregate.Beta},

	apiextensionsfeatures.CustomResourceFieldSelectors: {Default: true, PreRelease: featuregate.Beta},

  // documentation for Optional types for more information:
  // https://pkg.go.dev/github.com/google/cel-go/cel#OptionalTypes
  //
  // May not be set unless `oldSelf` is used in `rule`.
  //
  // +featureGate=CRDValidationRatcheting
  // +optional
  optional bool optionalOldSelf = 6;
}

// WebhookClientConfig contains the information to make a TLS connection with the webhook.
message WebhookClientConfig {

// Runs transition rule cases with OptionalOldSelf set to true on the schema
func TestOptionalOldSelf(t *testing.T) {
	featuregatetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, apiextensionsfeatures.CRDValidationRatcheting, true)

	tests := []struct {
		name   string
		schema *schema.Structural
		obj    interface{}
		oldObj interface{}
		errors []string // strings that error message must contain
	}{
		{

  // documentation for Optional types for more information:
  // https://pkg.go.dev/github.com/google/cel-go/cel#OptionalTypes
  //
  // May not be set unless `oldSelf` is used in `rule`.
  //
  // +featureGate=CRDValidationRatcheting
  // +optional
  optional bool optionalOldSelf = 6;
}

// WebhookClientConfig contains the information to make a TLS connection with the webhook.
message WebhookClientConfig {

`optionalOldSelf` API field in CustomResourceDefinition validation rules, which should only be allowed to be set when the CRDValidationRatcheting feature gate is enabled. Existing CustomResourceDefinition objects which have the field set will retain it on update, but new CustomResourceDefinition objects will not be permitted to set the field while the CRDValidationRatcheting feature gate is disabled. ([#122343](https://github.com/kubernetes/kubernetes/pull/122343), [@jpbetz](https://github.com/jpbetz))...