Export UnmarshalCaseSensitivePreserveInts, UnmarshalStrict, and NewDe…

…coderCaseSensitivePreserveInts

json.go

@@ -0,0 +1,139 @@
+/*
+Copyright 2021 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package json
+
+import (
+	gojson "encoding/json"
+	"fmt"
+	"io"
+
+	internaljson "sigs.k8s.io/json/internal/golang/encoding/json"
+)
+
+// Decoder describes the decoding API exposed by `encoding/json#Decoder`
+type Decoder interface {
+	Decode(v interface{}) error
+	Buffered() io.Reader
+	Token() (gojson.Token, error)
+	More() bool
+	InputOffset() int64
+}
+
+// NewDecoderCaseSensitivePreserveInts returns a decoder that matches the behavior of encoding/json#NewDecoder, with the following changes:
+// - When unmarshaling into a struct, JSON keys must case-sensitively match `json` tag names (for tagged struct fields)
+//   or struct field names (for untagged struct fields), or they are treated as unknown fields and discarded.
+// - When unmarshaling a number into an interface value, it is unmarshaled as an int64 if
+//   the JSON data does not contain a "." character and parses as an integer successfully and
+//   does not overflow int64. Otherwise, the number is unmarshaled as a float64.
+// - If a syntax error is returned, it will not be of type encoding/json#SyntaxError,
+//   but will be recognizeable by this package's IsSyntaxError() function.
+func NewDecoderCaseSensitivePreserveInts(r io.Reader) Decoder {
+	d := internaljson.NewDecoder(r)
+	d.CaseSensitive()
+	d.PreserveInts()
+	return d
+}
+
+// UnmarshalCaseSensitivePreserveInts parses the JSON-encoded data and stores the result in the value pointed to by v.
+//
+// UnmarshalCaseSensitivePreserveInts matches the behavior of encoding/json#Unmarshal, with the following changes:
+// - When unmarshaling into a struct, JSON keys must case-sensitively match `json` tag names (for tagged struct fields)
+//   or struct field names (for untagged struct fields), or they are treated as unknown fields and discarded.
+// - When unmarshaling a number into an interface value, it is unmarshaled as an int64 if
+//   the JSON data does not contain a "." character and parses as an integer successfully and
+//   does not overflow int64. Otherwise, the number is unmarshaled as a float64.
+// - If a syntax error is returned, it will not be of type encoding/json#SyntaxError,
+//   but will be recognizeable by this package's IsSyntaxError() function.
+func UnmarshalCaseSensitivePreserveInts(data []byte, v interface{}) error {
+	return internaljson.Unmarshal(
+		data,
+		v,
+		internaljson.CaseSensitive,
+		internaljson.PreserveInts,
+	)
+}
+
+type StrictOption int
+
+const (
+	// DisallowDuplicateFields returns strict errors if data contains duplicate fields
+	DisallowDuplicateFields StrictOption = 1
+
+	// DisallowUnknownFields returns strict errors if data contains unknown fields when decoding into typed structs
+	DisallowUnknownFields StrictOption = 2
+)
+
+// UnmarshalStrict parses the JSON-encoded data and stores the result in the value pointed to by v.
+// Unmarshaling is performed identically to UnmarshalCaseSensitivePreserveInts(), returning an error on failure.
+//
+// If parsing succeeds, additional strict checks as selected by `strictOptions` are performed
+// and a list of the strict failures (if any) are returned. If no `strictOptions` are selected,
+// all supported strict checks are performed.
+//
+// Currently supported strict checks are:
+// - DisallowDuplicateFields: ensure the data contains no duplicate fields
+// - DisallowUnknownFields: ensure the data contains no unknown fields (when decoding into typed structs)
+//
+// Additional strict checks may be added in the future.
+//
+// Note that the strict checks do not change what is stored in v.
+// For example, if duplicate fields are present, they will be parsed and stored in v,
+// and errors about the duplicate fields will be returned in the strict error list.
+func UnmarshalStrict(data []byte, v interface{}, strictOptions ...StrictOption) (strictErrors []error, err error) {
+	if len(strictOptions) == 0 {
+		err = internaljson.Unmarshal(data, v,
+			// options matching UnmarshalCaseSensitivePreserveInts
+			internaljson.CaseSensitive,
+			internaljson.PreserveInts,
+			// all strict options
+			internaljson.DisallowDuplicateFields,
+			internaljson.DisallowUnknownFields,
+		)
+	} else {
+		opts := make([]internaljson.UnmarshalOpt, 0, 2+len(strictOptions))
+		// options matching UnmarshalCaseSensitivePreserveInts
+		opts = append(opts, internaljson.CaseSensitive, internaljson.PreserveInts)
+		for _, strictOpt := range strictOptions {
+			switch strictOpt {
+			case DisallowDuplicateFields:
+				opts = append(opts, internaljson.DisallowDuplicateFields)
+			case DisallowUnknownFields:
+				opts = append(opts, internaljson.DisallowUnknownFields)
+			default:
+				return nil, fmt.Errorf("unknown strict option %d", strictOpt)
+			}
+		}
+		err = internaljson.Unmarshal(data, v, opts...)
+	}
+
+	if strictErr, ok := err.(*internaljson.UnmarshalStrictError); ok {
+		return strictErr.Errors, nil
+	}
+	return nil, err
+}
+
+// SyntaxErrorOffset returns if the specified error is a syntax error produced by encoding/json or this package.
+func SyntaxErrorOffset(err error) (isSyntaxError bool, offset int64) {
+	switch err := err.(type) {
+	case *gojson.SyntaxError:
+		return true, err.Offset
+	case *internaljson.SyntaxError:
+		return true, err.Offset
+	default:
+		return false, 0
+	}
+}