refactor(json): simplify strict mode error string construction (#693)

Author: jonchurch

HISTORY.md

@@ -1,3 +1,7 @@
+Unreleased
+=========================
+* refactor(json): simplify strict mode error string construction
+
 2.2.1 / 2025-11-24
 =========================
 

lib/types/json.js

@@ -102,11 +102,7 @@ function createStrictSyntaxError (str, char) {
   var partial = ''
 
   if (index !== -1) {
-    partial = str.substring(0, index) + JSON_SYNTAX_CHAR
-
-    for (var i = index + 1; i < str.length; i++) {
-      partial += JSON_SYNTAX_CHAR
-    }
+    partial = str.substring(0, index) + JSON_SYNTAX_CHAR.repeat(str.length - index)
   }
 
   try {