Migrate json wrapper and badjson to library

common/json/badjson/array.go

@@ -0,0 +1,46 @@
+package badjson
+
+import (
+	"bytes"
+
+	E "github.com/sagernet/sing/common/exceptions"
+	"github.com/sagernet/sing/common/json"
+)
+
+type JSONArray []any
+
+func (a JSONArray) MarshalJSON() ([]byte, error) {
+	return json.Marshal([]any(a))
+}
+
+func (a *JSONArray) UnmarshalJSON(content []byte) error {
+	decoder := json.NewDecoder(bytes.NewReader(content))
+	arrayStart, err := decoder.Token()
+	if err != nil {
+		return err
+	} else if arrayStart != json.Delim('[') {
+		return E.New("excepted array start, but got ", arrayStart)
+	}
+	err = a.decodeJSON(decoder)
+	if err != nil {
+		return err
+	}
+	arrayEnd, err := decoder.Token()
+	if err != nil {
+		return err
+	} else if arrayEnd != json.Delim(']') {
+		return E.New("excepted array end, but got ", arrayEnd)
+	}
+	return nil
+}
+
+func (a *JSONArray) decodeJSON(decoder *json.Decoder) error {
+	for decoder.More() {
+		item, err := decodeJSON(decoder)
+		if err != nil {
+			return err
+		}
+		*a = append(*a, item)
+	}
+	return nil
+}