JSTests/test262/test/built-ins/RegExp/prototype/Symbol.replace/coerce-lastindex.js

// Copyright (C) 2020 Alexey Shvayka. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.

/*---
esid: sec-regexp.prototype-@@replace
description: >
  Length coercion of "lastIndex" property of `this` value.
info: |
  RegExp.prototype [ @@replace ] ( string, replaceValue )

  [...]
  11. Repeat, while done is false
    a. Let result be ? RegExpExec(rx, S).
    b. If result is null, set done to true.
    c. Else,
      i. Append result to the end of results.
      ii. If global is false, set done to true.
      iii. Else,
        1. Let matchStr be ? ToString(? Get(result, "0")).
        2. If matchStr is the empty String, then
          a. Let thisIndex be ? ToLength(? Get(rx, "lastIndex")).
          b. Let nextIndex be AdvanceStringIndex(S, thisIndex, fullUnicode).
          c. Perform ? Set(rx, "lastIndex", nextIndex, true).
features: [Symbol.replace]
---*/

var r = /./g;
var execWasCalled = false;
var coercibleIndex = {
  valueOf: function() {
    return Math.pow(2, 54);
  },
};

var result = {
  length: 1,
  0: '',
  index: 0,
};

r.exec = function() {
  if (execWasCalled) {
    return null;
  }

  r.lastIndex = coercibleIndex;
  execWasCalled = true;
  return result;
};

assert.sameValue(r[Symbol.replace]('', ''), '');
assert.sameValue(r.lastIndex, Math.pow(2, 53));