feat: publish v1.0.0-rc.36-custom.1

relaykit/relayconvert/kitutil/json.go

@@ -0,0 +1,135 @@
+// Package kitutil holds the dependency-free helpers shared by the conversion
+// kit packages (dto, types, relayconvert). It moved out of the host's common
+// package as part of the relaykit extraction; common re-exports these for
+// host code.
+package kitutil
+
+import (
+	"bytes"
+	"encoding/json"
+	"io"
+	"unsafe"
+)
+
+// Codec is the JSON engine used by every kitutil JSON helper. The host may
+// replace it once at startup via SetCodec; relaykit itself never depends on a
+// third-party JSON library.
+type Codec interface {
+	Marshal(v any) ([]byte, error)
+	Unmarshal(data []byte, v any) error
+	Decode(r io.Reader, v any) error
+	Valid(data []byte) bool
+}
+
+// stdCodec is the default Codec, backed by encoding/json. It is the only place
+// in relaykit that calls the standard library's JSON functions directly.
+type stdCodec struct{}
+
+func (stdCodec) Marshal(v any) ([]byte, error) {
+	return json.Marshal(v)
+}
+
+func (stdCodec) Unmarshal(data []byte, v any) error {
+	return json.Unmarshal(data, v)
+}
+
+func (stdCodec) Decode(r io.Reader, v any) error {
+	return json.NewDecoder(r).Decode(v)
+}
+
+func (stdCodec) Valid(data []byte) bool {
+	return json.Valid(data)
+}
+
+var codec Codec = stdCodec{}
+
+// SetCodec installs the JSON engine behind every kitutil JSON helper, which
+// also covers the custom (Un)MarshalJSON methods on relaykit DTOs. Like
+// SetLogging it is meant to be called once during host startup before any
+// request is served; it is not synchronized against concurrent helper calls.
+// A nil codec is ignored so the standard-library default stays in place.
+func SetCodec(c Codec) {
+	if c == nil {
+		return
+	}
+	codec = c
+}
+
+func Unmarshal(data []byte, v any) error {
+	return codec.Unmarshal(data, v)
+}
+
+func UnmarshalJsonStr(data string, v any) error {
+	return codec.Unmarshal(StringToByteSlice(data), v)
+}
+
+func DecodeJson(reader io.Reader, v any) error {
+	return codec.Decode(reader, v)
+}
+
+func Marshal(v any) ([]byte, error) {
+	return codec.Marshal(v)
+}
+
+// Valid reports whether data is a syntactically valid JSON document.
+func Valid(data []byte) bool {
+	return codec.Valid(data)
+}
+
+func GetJsonType(data json.RawMessage) string {
+	trimmed := bytes.TrimSpace(data)
+	if len(trimmed) == 0 {
+		return "unknown"
+	}
+	firstChar := trimmed[0]
+	switch firstChar {
+	case '{':
+		return "object"
+	case '[':
+		return "array"
+	case '"':
+		return "string"
+	case 't', 'f':
+		return "boolean"
+	case 'n':
+		return "null"
+	default:
+		return "number"
+	}
+}
+
+// JsonRawMessageToString returns JSON strings as their decoded value and other JSON values as raw text.
+func JsonRawMessageToString(data json.RawMessage) string {
+	trimmed := bytes.TrimSpace(data)
+	if len(trimmed) == 0 || bytes.Equal(trimmed, []byte("null")) {
+		return ""
+	}
+	if trimmed[0] != '"' {
+		return string(trimmed)
+	}
+	var value string
+	if err := Unmarshal(trimmed, &value); err != nil {
+		return string(trimmed)
+	}
+	return value
+}
+
+func StringToByteSlice(s string) []byte {
+	tmp1 := (*[2]uintptr)(unsafe.Pointer(&s))
+	tmp2 := [3]uintptr{tmp1[0], tmp1[1], tmp1[1]}
+	return *(*[]byte)(unsafe.Pointer(&tmp2))
+}
+
+func Any2Type[T any](data any) (T, error) {
+	var zero T
+	encoded, err := Marshal(data)
+	if err != nil {
+		return zero, err
+	}
+	var res T
+	err = Unmarshal(encoded, &res)
+	if err != nil {
+		return zero, err
+	}
+	return res, nil
+}