Add CoveredByDeclarative to field error struct

- Introduce CoveredByDeclarative field to Error struct
- Add MarkCoveredByDeclarative method for Error and ErrorList
- Implement ExtractDeclarative method to filter out declaratively covered errors
- Update error constructors to include the new field
- Add corresponding test cases for new declarative validation functionality

staging/src/k8s.io/apimachinery/pkg/util/validation/field/errors.go

@@ -47,6 +47,11 @@ type Error struct {
 	// Origin should be set in the most deeply nested validation function that
 	// can still identify the unique source of the error.
 	Origin string
+
+	// CoveredByDeclarative is true when this error is covered by declarative
+	// validation. This field is to identify errors from imperative validation
+	// that should also be caught by declarative validation.
+	CoveredByDeclarative bool
 }
 
 var _ error = &Error{}
@@ -116,6 +121,12 @@ func (e *Error) WithOrigin(o string) *Error {
 	return e
 }
 
+// MarkCoveredByDeclarative marks the error as covered by declarative validation.
+func (e *Error) MarkCoveredByDeclarative() *Error {
+	e.CoveredByDeclarative = true
+	return e
+}
+
 // ErrorType is a machine readable value providing more detail about why
 // a field is invalid.  These values are expected to match 1-1 with
 // CauseType in api/types.go.
@@ -189,32 +200,32 @@ func (t ErrorType) String() string {
 
 // TypeInvalid returns a *Error indicating "type is invalid"
 func TypeInvalid(field *Path, value interface{}, detail string) *Error {
-	return &Error{ErrorTypeTypeInvalid, field.String(), value, detail, ""}
+	return &Error{ErrorTypeTypeInvalid, field.String(), value, detail, "", false}
 }
 
 // NotFound returns a *Error indicating "value not found".  This is
 // used to report failure to find a requested value (e.g. looking up an ID).
 func NotFound(field *Path, value interface{}) *Error {
-	return &Error{ErrorTypeNotFound, field.String(), value, "", ""}
+	return &Error{ErrorTypeNotFound, field.String(), value, "", "", false}
 }
 
 // Required returns a *Error indicating "value required".  This is used
 // to report required values that are not provided (e.g. empty strings, null
 // values, or empty arrays).
 func Required(field *Path, detail string) *Error {
-	return &Error{ErrorTypeRequired, field.String(), "", detail, ""}
+	return &Error{ErrorTypeRequired, field.String(), "", detail, "", false}
 }
 
 // Duplicate returns a *Error indicating "duplicate value".  This is
 // used to report collisions of values that must be unique (e.g. names or IDs).
 func Duplicate(field *Path, value interface{}) *Error {
-	return &Error{ErrorTypeDuplicate, field.String(), value, "", ""}
+	return &Error{ErrorTypeDuplicate, field.String(), value, "", "", false}
 }
 
 // Invalid returns a *Error indicating "invalid value".  This is used
 // to report malformed values (e.g. failed regex match, too long, out of bounds).
 func Invalid(field *Path, value interface{}, detail string) *Error {
-	return &Error{ErrorTypeInvalid, field.String(), value, detail, ""}
+	return &Error{ErrorTypeInvalid, field.String(), value, detail, "", false}
 }
 
 // NotSupported returns a *Error indicating "unsupported value".
@@ -229,7 +240,7 @@ func NotSupported[T ~string](field *Path, value interface{}, validValues []T) *E
 		}
 		detail = "supported values: " + strings.Join(quotedValues, ", ")
 	}
-	return &Error{ErrorTypeNotSupported, field.String(), value, detail, ""}
+	return &Error{ErrorTypeNotSupported, field.String(), value, detail, "", false}
 }
 
 // Forbidden returns a *Error indicating "forbidden".  This is used to
@@ -237,7 +248,7 @@ func NotSupported[T ~string](field *Path, value interface{}, validValues []T) *E
 // some conditions, but which are not permitted by current conditions (e.g.
 // security policy).
 func Forbidden(field *Path, detail string) *Error {
-	return &Error{ErrorTypeForbidden, field.String(), "", detail, ""}
+	return &Error{ErrorTypeForbidden, field.String(), "", detail, "", false}
 }
 
 // TooLong returns a *Error indicating "too long".  This is used to report that
@@ -251,7 +262,7 @@ func TooLong(field *Path, value interface{}, maxLength int) *Error {
 	} else {
 		msg = "value is too long"
 	}
-	return &Error{ErrorTypeTooLong, field.String(), "<value omitted>", msg, ""}
+	return &Error{ErrorTypeTooLong, field.String(), "<value omitted>", msg, "", false}
 }
 
 // TooLongMaxLength returns a *Error indicating "too long".
@@ -279,14 +290,14 @@ func TooMany(field *Path, actualQuantity, maxQuantity int) *Error {
 		actual = omitValue
 	}
 
-	return &Error{ErrorTypeTooMany, field.String(), actual, msg, ""}
+	return &Error{ErrorTypeTooMany, field.String(), actual, msg, "", false}
 }
 
 // InternalError returns a *Error indicating "internal error".  This is used
 // to signal that an error was found that was not directly related to user
 // input.  The err argument must be non-nil.
 func InternalError(field *Path, err error) *Error {
-	return &Error{ErrorTypeInternal, field.String(), nil, err.Error(), ""}
+	return &Error{ErrorTypeInternal, field.String(), nil, err.Error(), "", false}
 }
 
 // ErrorList holds a set of Errors.  It is plausible that we might one day have
@@ -313,6 +324,14 @@ func (list ErrorList) WithOrigin(origin string) ErrorList {
 	return list
 }
 
+// MarkCoveredByDeclarative marks all errors in the list as covered by declarative validation.
+func (list ErrorList) MarkCoveredByDeclarative() ErrorList {
+	for _, err := range list {
+		err.CoveredByDeclarative = true
+	}
+	return list
+}
+
 // ToAggregate converts the ErrorList into an errors.Aggregate.
 func (list ErrorList) ToAggregate() utilerrors.Aggregate {
 	if len(list) == 0 {
@@ -349,3 +368,25 @@ func (list ErrorList) Filter(fns ...utilerrors.Matcher) ErrorList {
 	// FilterOut takes an Aggregate and returns an Aggregate
 	return fromAggregate(err.(utilerrors.Aggregate))
 }
+
+// ExtractCoveredByDeclarative returns a new ErrorList containing only the errors that should be covered by declarative validation.
+func (list ErrorList) ExtractCoveredByDeclarative() ErrorList {
+	newList := ErrorList{}
+	for _, err := range list {
+		if err.CoveredByDeclarative {
+			newList = append(newList, err)
+		}
+	}
+	return newList
+}
+
+// RemoveCoveredByDeclarative returns a new ErrorList containing only the errors that should not be covered by declarative validation.
+func (list ErrorList) RemoveCoveredByDeclarative() ErrorList {
+	newList := ErrorList{}
+	for _, err := range list {
+		if !err.CoveredByDeclarative {
+			newList = append(newList, err)
+		}
+	}
+	return newList
+}

staging/src/k8s.io/apimachinery/pkg/util/validation/field/errors_test.go

@@ -18,6 +18,7 @@ package field
 
 import (
 	"fmt"
+	"reflect"
 	"strings"
 	"testing"
 )
@@ -211,3 +212,92 @@ func TestErrorListOrigin(t *testing.T) {
 		}
 	}
 }
+
+func TestErrorMarkDeclarative(t *testing.T) {
+	// Test for single Error
+	err := Invalid(NewPath("field"), "value", "detail")
+	if err.CoveredByDeclarative {
+		t.Errorf("New error should not be declarative by default")
+	}
+
+	// Mark as declarative
+	err.MarkCoveredByDeclarative() //nolint:errcheck // The "error" here is not an unexpected error from the function.
+	if !err.CoveredByDeclarative {
+		t.Errorf("Error should be declarative after marking")
+	}
+}
+
+func TestErrorListMarkDeclarative(t *testing.T) {
+	// Test for ErrorList
+	list := ErrorList{
+		Invalid(NewPath("field1"), "value1", "detail1"),
+		Invalid(NewPath("field2"), "value2", "detail2"),
+	}
+
+	// Verify none are declarative by default
+	for i, err := range list {
+		if err.CoveredByDeclarative {
+			t.Errorf("Error %d should not be declarative by default", i)
+		}
+	}
+
+	// Mark list as declarative
+	list.MarkCoveredByDeclarative()
+
+	// Verify all errors in the list are now declarative
+	for i, err := range list {
+		if !err.CoveredByDeclarative {
+			t.Errorf("Error %d should be declarative after marking the list", i)
+		}
+	}
+}
+
+func TestErrorListExtractCoveredByDeclarative(t *testing.T) {
+	testCases := []struct {
+		list         ErrorList
+		expectedList ErrorList
+	}{
+		{
+			ErrorList{},
+			ErrorList{},
+		},
+		{
+			ErrorList{Invalid(NewPath("field1"), nil, "")},
+			ErrorList{},
+		},
+		{
+			ErrorList{Invalid(NewPath("field1"), nil, "").MarkCoveredByDeclarative(), Required(NewPath("field2"), "detail2")},
+			ErrorList{Invalid(NewPath("field1"), nil, "").MarkCoveredByDeclarative()},
+		},
+	}
+
+	for _, tc := range testCases {
+		got := tc.list.ExtractCoveredByDeclarative()
+		if !reflect.DeepEqual(got, tc.expectedList) {
+			t.Errorf("For list %v, expected %v, got %v", tc.list, tc.expectedList, got)
+		}
+	}
+}
+
+func TestErrorListRemoveCoveredByDeclarative(t *testing.T) {
+	testCases := []struct {
+		list         ErrorList
+		expectedList ErrorList
+	}{
+		{
+			ErrorList{},
+			ErrorList{},
+		},
+		{
+			ErrorList{Invalid(NewPath("field1"), nil, "").MarkCoveredByDeclarative(), Required(NewPath("field2"), "detail2")},
+			ErrorList{Required(NewPath("field2"), "detail2")},
+		},
+	}
+
+	for _, tc := range testCases {
+		got := tc.list.RemoveCoveredByDeclarative()
+		if !reflect.DeepEqual(got, tc.expectedList) {
+			t.Errorf("For list %v, expected %v, got %v", tc.list, tc.expectedList, got)
+		}
+	}
+}