core-js/tests/unit-global/es.regexp.flags.js

/* eslint-disable prefer-regex-literals, regexp/sort-flags, regexp/no-useless-flag -- required for testing */
import { DESCRIPTORS } from '../helpers/constants.js';

if (DESCRIPTORS) {
  QUnit.test('RegExp#flags', assert => {
    assert.nonEnumerable(RegExp.prototype, 'flags');
    assert.same(/./g.flags, 'g', '/./g.flags is "g"');
    assert.same(/./.flags, '', '/./.flags is ""');
    assert.same(RegExp('.', 'gim').flags, 'gim', 'RegExp(".", "gim").flags is "gim"');
    assert.same(RegExp('.').flags, '', 'RegExp(".").flags is ""');
    assert.same(/./gim.flags, 'gim', '/./gim.flags is "gim"');
    assert.same(/./gmi.flags, 'gim', '/./gmi.flags is "gim"');
    assert.same(/./mig.flags, 'gim', '/./mig.flags is "gim"');
    assert.same(/./mgi.flags, 'gim', '/./mgi.flags is "gim"');

    let INDICES_SUPPORT = true;
    try {
      RegExp('.', 'd');
    } catch {
      INDICES_SUPPORT = false;
    }

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

    function addGetter(key, chr) {
      Object.defineProperty(O, key, { get() {
        calls += chr;
        return true;
      } });
    }

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

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

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

    const result = Object.getOwnPropertyDescriptor(RegExp.prototype, 'flags').get.call(O);

    assert.same(result, expected, 'proper order, result');
    assert.same(calls, expected, 'proper order, calls');
  });
}