initial go implementation

internal/utils/format/json.go

@@ -0,0 +1,31 @@
+package format
+
+import (
+	"bytes"
+	"encoding/json"
+)
+
+func FormatJSON(input string) string {
+	var data any
+	if err := json.Unmarshal([]byte(input), &data); err != nil {
+		var out bytes.Buffer
+		if err := json.Indent(&out, []byte(input), "", "  "); err == nil {
+			return out.String()
+		}
+		return input
+	}
+
+	var out bytes.Buffer
+	encoder := json.NewEncoder(&out)
+	encoder.SetEscapeHTML(false)
+	encoder.SetIndent("", "  ")
+	if err := encoder.Encode(data); err != nil {
+		return input
+	}
+
+	formatted := out.String()
+	if len(formatted) > 0 && formatted[len(formatted)-1] == '\n' {
+		formatted = formatted[:len(formatted)-1]
+	}
+	return formatted
+}