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node_modules/core-js/modules/es.string.to-well-formed.js

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+'use strict';
+var $ = require('../internals/export');
+var call = require('../internals/function-call');
+var uncurryThis = require('../internals/function-uncurry-this');
+var requireObjectCoercible = require('../internals/require-object-coercible');
+var toString = require('../internals/to-string');
+var fails = require('../internals/fails');
+
+var $Array = Array;
+var charAt = uncurryThis(''.charAt);
+var charCodeAt = uncurryThis(''.charCodeAt);
+var join = uncurryThis([].join);
+// eslint-disable-next-line es/no-string-prototype-iswellformed-towellformed -- safe
+var $toWellFormed = ''.toWellFormed;
+var REPLACEMENT_CHARACTER = '\uFFFD';
+
+// Safari bug
+var TO_STRING_CONVERSION_BUG = $toWellFormed && fails(function () {
+  return call($toWellFormed, 1) !== '1';
+});
+
+// `String.prototype.toWellFormed` method
+// https://github.com/tc39/proposal-is-usv-string
+$({ target: 'String', proto: true, forced: TO_STRING_CONVERSION_BUG }, {
+  toWellFormed: function toWellFormed() {
+    var S = toString(requireObjectCoercible(this));
+    if (TO_STRING_CONVERSION_BUG) return call($toWellFormed, S);
+    var length = S.length;
+    var result = $Array(length);
+    for (var i = 0; i < length; i++) {
+      var charCode = charCodeAt(S, i);
+      // single UTF-16 code unit
+      if ((charCode & 0xF800) != 0xD800) result[i] = charAt(S, i);
+      // unpaired surrogate
+      else if (charCode >= 0xDC00 || i + 1 >= length || (charCodeAt(S, i + 1) & 0xFC00) != 0xDC00) result[i] = REPLACEMENT_CHARACTER;
+      // surrogate pair
+      else {
+        result[i] = charAt(S, i);
+        result[++i] = charAt(S, i);
+      }
+    } return join(result, '');
+  }
+});