From bf06c45b29fabd1652f91ed6a8fde6d2e600cf1a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=B8=96=E7=95=8C?= <i@sekai.icu>
Date: Tue, 12 Dec 2023 20:13:52 +0800
Subject: [PATCH] badjson: Add UnmarshalExtended

---
 common/json/unmarshal.go | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)
 create mode 100644 common/json/unmarshal.go

diff --git a/common/json/unmarshal.go b/common/json/unmarshal.go
new file mode 100644
index 00000000..fa6452d1
--- /dev/null
+++ b/common/json/unmarshal.go
@@ -0,0 +1,25 @@
+package json
+
+import (
+	"bytes"
+	"strings"
+
+	"github.com/sagernet/sing/common"
+	E "github.com/sagernet/sing/common/exceptions"
+)
+
+func UnmarshalExtended[T any](content []byte) (T, error) {
+	decoder := NewDecoder(NewCommentFilter(bytes.NewReader(content)))
+	var value T
+	err := decoder.Decode(&value)
+	if err == nil {
+		return value, err
+	}
+	if syntaxError, isSyntaxError := err.(*SyntaxError); isSyntaxError {
+		prefix := string(content[:syntaxError.Offset])
+		row := strings.Count(prefix, "\n") + 1
+		column := len(prefix) - strings.LastIndex(prefix, "\n") - 1
+		return common.DefaultValue[T](), E.Extend(syntaxError, "row ", row, ", column ", column)
+	}
+	return common.DefaultValue[T](), err
+}