core-js/modules/es.regexp.flags.js

'use strict';
var global = require('../internals/global');
var DESCRIPTORS = require('../internals/descriptors');
var defineBuiltInAccessor = require('../internals/define-built-in-accessor');
var regExpFlags = require('../internals/regexp-flags');
var fails = require('../internals/fails');

// babel-minify and Closure Compiler transpiles RegExp('.', 'd') -> /./d and it causes SyntaxError
var RegExp = global.RegExp;
var RegExpPrototype = RegExp.prototype;

var FORCED = DESCRIPTORS && fails(function () {
  var INDICES_SUPPORT = true;
  try {
    RegExp('.', 'd');
  } catch (error) {
    INDICES_SUPPORT = false;
  }

  var O = {};
  // modern V8 bug
  var calls = '';
  var expected = INDICES_SUPPORT ? 'dgimsy' : 'gimsy';

  var addGetter = function (key, chr) {
    // eslint-disable-next-line es/no-object-defineproperty -- safe
    Object.defineProperty(O, key, { get: function () {
      calls += chr;
      return true;
    } });
  };

  var pairs = {
    dotAll: 's',
    global: 'g',
    ignoreCase: 'i',
    multiline: 'm',
    sticky: 'y'
  };

  if (INDICES_SUPPORT) pairs.hasIndices = 'd';

  for (var key in pairs) addGetter(key, pairs[key]);

  // eslint-disable-next-line es/no-object-getownpropertydescriptor -- safe
  var result = Object.getOwnPropertyDescriptor(RegExpPrototype, 'flags').get.call(O);

  return result !== expected || calls !== expected;
});

// `RegExp.prototype.flags` getter
// https://tc39.es/ecma262/#sec-get-regexp.prototype.flags
if (FORCED) defineBuiltInAccessor(RegExpPrototype, 'flags', {
  configurable: true,
  get: regExpFlags
});