Add server-side metadata unknown field validation

vendor/sigs.k8s.io/json/internal/golang/encoding/json/decode.go

@@ -695,7 +695,7 @@ func (d *decodeState) object(v reflect.Value) error {
 					seenKeys = map[string]struct{}{}
 				}
 				if _, seen := seenKeys[fieldName]; seen {
-					d.saveStrictError(d.newFieldError("duplicate field", fieldName))
+					d.saveStrictError(d.newFieldError(duplicateStrictErrType, fieldName))
 				} else {
 					seenKeys[fieldName] = struct{}{}
 				}
@@ -711,7 +711,7 @@ func (d *decodeState) object(v reflect.Value) error {
 				var seenKeys uint64
 				checkDuplicateField = func(fieldNameIndex int, fieldName string) {
 					if seenKeys&(1<<fieldNameIndex) != 0 {
-						d.saveStrictError(d.newFieldError("duplicate field", fieldName))
+						d.saveStrictError(d.newFieldError(duplicateStrictErrType, fieldName))
 					} else {
 						seenKeys = seenKeys | (1 << fieldNameIndex)
 					}
@@ -724,7 +724,7 @@ func (d *decodeState) object(v reflect.Value) error {
 						seenIndexes = make([]bool, len(fields.list))
 					}
 					if seenIndexes[fieldNameIndex] {
-						d.saveStrictError(d.newFieldError("duplicate field", fieldName))
+						d.saveStrictError(d.newFieldError(duplicateStrictErrType, fieldName))
 					} else {
 						seenIndexes[fieldNameIndex] = true
 					}
@@ -836,7 +836,7 @@ func (d *decodeState) object(v reflect.Value) error {
 				d.errorContext.Struct = t
 				d.appendStrictFieldStackKey(f.name)
 			} else if d.disallowUnknownFields {
-				d.saveStrictError(d.newFieldError("unknown field", string(key)))
+				d.saveStrictError(d.newFieldError(unknownStrictErrType, string(key)))
 			}
 		}
 
@@ -1231,7 +1231,7 @@ func (d *decodeState) objectInterface() map[string]interface{} {
 
 		if d.disallowDuplicateFields {
 			if _, exists := m[key]; exists {
-				d.saveStrictError(d.newFieldError("duplicate field", key))
+				d.saveStrictError(d.newFieldError(duplicateStrictErrType, key))
 			}
 		}
 

vendor/sigs.k8s.io/json/internal/golang/encoding/json/kubernetes_patch.go

@@ -18,7 +18,6 @@ package json
 
 import (
 	gojson "encoding/json"
-	"fmt"
 	"strconv"
 	"strings"
 )
@@ -71,17 +70,23 @@ func (d *Decoder) DisallowDuplicateFields() {
 	d.d.disallowDuplicateFields = true
 }
 
-func (d *decodeState) newFieldError(msg, field string) error {
+func (d *decodeState) newFieldError(errType strictErrType, field string) *strictError {
 	if len(d.strictFieldStack) > 0 {
-		return fmt.Errorf("%s %q", msg, strings.Join(d.strictFieldStack, "")+"."+field)
+		return &strictError{
+			ErrType: errType,
+			Path:    strings.Join(d.strictFieldStack, "") + "." + field,
+		}
 	} else {
-		return fmt.Errorf("%s %q", msg, field)
+		return &strictError{
+			ErrType: errType,
+			Path:    field,
+		}
 	}
 }
 
 // saveStrictError saves a strict decoding error,
 // for reporting at the end of the unmarshal if no other errors occurred.
-func (d *decodeState) saveStrictError(err error) {
+func (d *decodeState) saveStrictError(err *strictError) {
 	// prevent excessive numbers of accumulated errors
 	if len(d.savedStrictErrors) >= 100 {
 		return
@@ -118,6 +123,33 @@ func (d *decodeState) appendStrictFieldStackIndex(i int) {
 	d.strictFieldStack = append(d.strictFieldStack, "[", strconv.Itoa(i), "]")
 }
 
+type strictErrType string
+
+const (
+	unknownStrictErrType   strictErrType = "unknown field"
+	duplicateStrictErrType strictErrType = "duplicate field"
+)
+
+// strictError is a strict decoding error
+// It has an ErrType (either unknown or duplicate)
+// and a path to the erroneous field
+type strictError struct {
+	ErrType strictErrType
+	Path    string
+}
+
+func (e *strictError) Error() string {
+	return string(e.ErrType) + " " + strconv.Quote(e.Path)
+}
+
+func (e *strictError) FieldPath() string {
+	return e.Path
+}
+
+func (e *strictError) SetFieldPath(path string) {
+	e.Path = path
+}
+
 // UnmarshalStrictError holds errors resulting from use of strict disallow___ decoder directives.
 // If this is returned from Unmarshal(), it means the decoding was successful in all other respects.
 type UnmarshalStrictError struct {

vendor/sigs.k8s.io/json/json.go

@@ -137,3 +137,11 @@ func SyntaxErrorOffset(err error) (isSyntaxError bool, offset int64) {
 		return false, 0
 	}
 }
+
+// FieldError are errors that provide access to
+// the path of the erroneous field
+type FieldError interface {
+	Error() string
+	FieldPath() string
+	SetFieldPath(path string)
+}