feat: Add Origin field to Error and related methods

This change introducing a new field in Error. It would be used in testing to compare the expected errors without matching the detail strings.

Co-authored-by: Tim Hockin <thockin@google.com>

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

@@ -33,6 +33,20 @@ type Error struct {
 	Field    string
 	BadValue interface{}
 	Detail   string
+
+	// Origin uniquely identifies where this error was generated from. It is used in testing to
+	// compare expected errors against actual errors without relying on exact detail string matching.
+	// This allows tests to verify the correct validation logic triggered the error
+	// regardless of how the error message might be formatted or localized.
+	//
+	// The value should be either:
+	// - A simple camelCase identifier (e.g., "maximum", "maxItems")
+	// - A structured format using "format=<dash-style-identifier>" for validation errors related to specific formats
+	//   (e.g., "format=dns-label", "format=qualified-name")
+	//
+	// Origin should be set in the most deeply nested validation function that
+	// can still identify the unique source of the error.
+	Origin string
 }
 
 var _ error = &Error{}
@@ -96,6 +110,12 @@ func (v *Error) ErrorBody() string {
 	return s
 }
 
+// WithOrigin adds origin information to the FieldError
+func (v *Error) WithOrigin(o string) *Error {
+	v.Origin = o
+	return v
+}
+
 // 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.
@@ -169,32 +189,32 @@ 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, ""}
 }
 
 // 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, "", ""}
 }
 
 // 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, ""}
 }
 
 // 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, "", ""}
 }
 
 // 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, ""}
 }
 
 // NotSupported returns a *Error indicating "unsupported value".
@@ -209,7 +229,7 @@ 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, ""}
 }
 
 // Forbidden returns a *Error indicating "forbidden".  This is used to
@@ -217,7 +237,7 @@ 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, ""}
 }
 
 // TooLong returns a *Error indicating "too long".  This is used to report that
@@ -231,7 +251,7 @@ 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, ""}
 }
 
 // TooLongMaxLength returns a *Error indicating "too long".
@@ -259,14 +279,14 @@ func TooMany(field *Path, actualQuantity, maxQuantity int) *Error {
 		actual = omitValue
 	}
 
-	return &Error{ErrorTypeTooMany, field.String(), actual, msg}
+	return &Error{ErrorTypeTooMany, field.String(), actual, msg, ""}
 }
 
 // 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(), ""}
 }
 
 // ErrorList holds a set of Errors.  It is plausible that we might one day have
@@ -285,6 +305,14 @@ func NewErrorTypeMatcher(t ErrorType) utilerrors.Matcher {
 	}
 }
 
+// WithOrigin sets the origin for all errors in the list and returns the updated list.
+func (list ErrorList) WithOrigin(origin string) ErrorList {
+	for _, err := range list {
+		err.Origin = origin
+	}
+	return list
+}
+
 // ToAggregate converts the ErrorList into an errors.Aggregate.
 func (list ErrorList) ToAggregate() utilerrors.Aggregate {
 	if len(list) == 0 {

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

@@ -173,3 +173,41 @@ func TestNotSupported(t *testing.T) {
 		t.Errorf("Expected: %s\n, but got: %s\n", expected, notSupported.ErrorBody())
 	}
 }
+
+func TestErrorOrigin(t *testing.T) {
+	err := Invalid(NewPath("field"), "value", "detail")
+
+	// Test WithOrigin
+	newErr := err.WithOrigin("origin1")
+	if newErr.Origin != "origin1" {
+		t.Errorf("Expected Origin to be 'origin1', got '%s'", newErr.Origin)
+	}
+	if err.Origin != "origin1" {
+		t.Errorf("Expected Origin to be 'origin1', got '%s'", err.Origin)
+	}
+}
+
+func TestErrorListOrigin(t *testing.T) {
+	// Create an ErrorList with multiple errors
+	list := ErrorList{
+		Invalid(NewPath("field1"), "value1", "detail1"),
+		Invalid(NewPath("field2"), "value2", "detail2"),
+		Required(NewPath("field3"), "detail3"),
+	}
+
+	// Test WithOrigin
+	newList := list.WithOrigin("origin1")
+	// Check that WithOrigin returns the modified list
+	for i, err := range newList {
+		if err.Origin != "origin1" {
+			t.Errorf("Error %d: Expected Origin to be 'origin2', got '%s'", i, err.Origin)
+		}
+	}
+
+	// Check that the original list was also modified (WithOrigin modifies and returns the same list)
+	for i, err := range list {
+		if err.Origin != "origin1" {
+			t.Errorf("Error %d: Expected original list Origin to be 'origin2', got '%s'", i, err.Origin)
+		}
+	}
+}