✨feat(crd): Preserve Enum validation for IntOrString type in CRD generation

pkg/crd/flatten.go

@@ -75,6 +75,15 @@ func flattenAllOfInto(dst *apiextensionsv1.JSONSchemaProps, src apiextensionsv1.
 		case "Title", "Description", "Example", "ExternalDocs":
 			// don't merge because we pre-merge to properly preserve field docs
 			continue
+		case "Enum":
+			// Enum from field markers should be preserved even if the type schema doesn't have it
+			// This is important for types like IntOrString where field-level enum validation
+			// needs to be preserved during flattening
+			if len(src.Enum) > 0 && len(dst.Enum) == 0 {
+				dst.Enum = make([]apiextensionsv1.JSON, len(src.Enum))
+				copy(dst.Enum, src.Enum)
+			}
+			continue
 		}
 		srcField := srcVal.Field(i)
 		fldTyp := srcField.Type()

pkg/crd/testdata/cronjob_types.go

@@ -271,6 +271,12 @@ type CronJobSpec struct {
 	// +kubebuilder:validation:Pattern="^((100|[0-9]{1,2})%|[0-9]+)$"
 	IntOrStringWithAPattern *intstr.IntOrString `json:"intOrStringWithAPattern,omitempty"`
 
+	// This tests that an IntOrString can have enum validation.
+	// The XIntOrString marker is required for applying enum to IntOrString.
+	// +kubebuilder:validation:XIntOrString
+	// +kubebuilder:validation:Enum=1;2;"foo";"bar"
+	IntOrStringWithEnum *intstr.IntOrString `json:"intOrStringWithEnum,omitempty"`
+
 	// Checks that nested maps work
 	NestedMap map[string]map[string]string `json:"nestedMap,omitempty"`
 

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

@@ -319,6 +319,19 @@ spec:
                 minLength: 2
                 pattern: ^((100|[0-9]{1,2})%|[0-9]+)$
                 x-kubernetes-int-or-string: true
+              intOrStringWithEnum:
+                anyOf:
+                - type: integer
+                - type: string
+                description: |-
+                  This tests that an IntOrString can have enum validation.
+                  The XIntOrString marker is required for applying enum to IntOrString.
+                enum:
+                - 1
+                - 2
+                - foo
+                - bar
+                x-kubernetes-int-or-string: true
               intWithValidations:
                 maximum: 2
                 minimum: -2