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

/* eslint-disable prefer-regex-literals -- required for testing */
import { DESCRIPTORS } from '../helpers/constants.js';

QUnit.test('RegExp#exec lastIndex updating', assert => {
  let re = /b/;
  assert.same(re.lastIndex, 0, '.lastIndex starts at 0 for non-global regexps');
  re.exec('abc');
  assert.same(re.lastIndex, 0, '.lastIndex is not updated for non-global regexps');

  re = /b/g;
  assert.same(re.lastIndex, 0, '.lastIndex starts at 0 for global regexps');
  re.exec('abc');
  assert.same(re.lastIndex, 2, '.lastIndex is updated for global regexps');

  re = /b*/;
  re.exec('a');
  assert.same(re.lastIndex, 0, '.lastIndex is not updated for non-global regexps if the match is empty');

  re = /b*/g;
  re.exec('a');
  assert.same(re.lastIndex, 0, '.lastIndex is not updated for global regexps if the match is empty');
});

QUnit.test('RegExp#exec capturing groups', assert => {
  assert.deepEqual(/(a?)/.exec('x'), ['', ''], '/(a?)/.exec("x") returns ["", ""]');
  assert.deepEqual(/(a)?/.exec('x'), ['', undefined], '/(a)?/.exec("x") returns ["", undefined]');

  // @nicolo-ribaudo: I don't know how to fix this in IE8. For the `/(a)?/` case it is fixed using
  // #replace, but here also #replace is buggy :(
  // assert.deepEqual(/(a?)?/.exec('x'), ['', undefined], '/(a?)?/.exec("x") returns ["", undefined]');
});

if (DESCRIPTORS) {
  QUnit.test('RegExp#exec regression', assert => {
    assert.throws(() => /l/.exec(Symbol('RegExp#exec test')), 'throws on symbol argument');
  });

  QUnit.test('RegExp#exec sticky', assert => {
    const re = new RegExp('a', 'y');
    const str = 'bbabaab';
    assert.same(re.lastIndex, 0, '#1');

    assert.same(re.exec(str), null, '#2');
    assert.same(re.lastIndex, 0, '#3');

    re.lastIndex = 1;
    assert.same(re.exec(str), null, '#4');
    assert.same(re.lastIndex, 0, '#5');

    re.lastIndex = 2;
    const result = re.exec(str);
    assert.deepEqual(result, ['a'], '#6');
    assert.same(result.index, 2, '#7');
    assert.same(result.input, str, 'match.input is the original string');
    assert.same(re.lastIndex, 3, '#8');

    assert.same(re.exec(str), null, '#9');
    assert.same(re.lastIndex, 0, '#10');

    re.lastIndex = 4;
    assert.deepEqual(re.exec(str), ['a'], '#11');
    assert.same(re.lastIndex, 5, '#12');

    assert.deepEqual(re.exec(str), ['a'], '#13');
    assert.same(re.lastIndex, 6, '#14');

    assert.same(re.exec(str), null, '#15');
    assert.same(re.lastIndex, 0, '#16');
  });

  QUnit.test('RegExp#exec sticky anchored', assert => {
    const regex = new RegExp('^foo', 'y');
    assert.deepEqual(regex.exec('foo'), ['foo'], '#1');
    regex.lastIndex = 2;
    assert.same(regex.exec('..foo'), null, '#2');
    regex.lastIndex = 2;
    assert.same(regex.exec('.\nfoo'), null, '#3');

    const regex2 = new RegExp('^foo', 'my');
    regex2.lastIndex = 2;
    assert.same(regex2.exec('..foo'), null, '#4');
    regex2.lastIndex = 2;
    assert.deepEqual(regex2.exec('.\nfoo'), ['foo'], '#5');
    assert.same(regex2.lastIndex, 5, '#6');

    // all line terminators should allow ^ to match in multiline+sticky mode
    const regex3 = new RegExp('^bar', 'my');
    regex3.lastIndex = 2;
    assert.deepEqual(regex3.exec('.\rbar'), ['bar'], 'multiline sticky after \\r');
    const regex4 = new RegExp('^bar', 'my');
    regex4.lastIndex = 2;
    assert.deepEqual(regex4.exec('.\u2028bar'), ['bar'], 'multiline sticky after \\u2028');
    const regex5 = new RegExp('^bar', 'my');
    regex5.lastIndex = 2;
    assert.deepEqual(regex5.exec('.\u2029bar'), ['bar'], 'multiline sticky after \\u2029');
  });

  QUnit.test('RegExp#exec sticky with alternation', assert => {
    const re = new RegExp('a|b', 'y');
    re.lastIndex = 1;
    const result = re.exec('cb');
    assert.deepEqual(result, ['b'], 'alternation matches non-first alternative at lastIndex');
    assert.same(re.lastIndex, 2, 'lastIndex updated correctly');
  });
}