--- /dev/null
+var $ = require('../internals/export');
+var getBuiltIn = require('../internals/get-built-in');
+var fails = require('../internals/fails');
+
+var $stringify = getBuiltIn('JSON', 'stringify');
+var re = /[\uD800-\uDFFF]/g;
+var low = /^[\uD800-\uDBFF]$/;
+var hi = /^[\uDC00-\uDFFF]$/;
+
+var fix = function (match, offset, string) {
+ var prev = string.charAt(offset - 1);
+ var next = string.charAt(offset + 1);
+ if ((low.test(match) && !hi.test(next)) || (hi.test(match) && !low.test(prev))) {
+ return '\\u' + match.charCodeAt(0).toString(16);
+ } return match;
+};
+
+var FORCED = fails(function () {
+ return $stringify('\uDF06\uD834') !== '"\\udf06\\ud834"'
+ || $stringify('\uDEAD') !== '"\\udead"';
+});
+
+if ($stringify) {
+ // `JSON.stringify` method
+ // https://tc39.es/ecma262/#sec-json.stringify
+ // https://github.com/tc39/proposal-well-formed-stringify
+ $({ target: 'JSON', stat: true, forced: FORCED }, {
+ // eslint-disable-next-line no-unused-vars -- required for `.length`
+ stringify: function stringify(it, replacer, space) {
+ var result = $stringify.apply(null, arguments);
+ return typeof result == 'string' ? result.replace(re, fix) : result;
+ }
+ });
+}