Named capture failed

[bluelovers]

node.js v14.4.0

import XRegExp from 'xregexp';

var repeatedWords = XRegExp('\\b(?<word>[a-z]+)\\s+\\k<word>\\b', 'gi');

console.dir(repeatedWords.exec('The the test data'))

console.dir('The the test data'.match(repeatedWords))

[
  'The the',
  'The',
  index: 0,
  input: 'The the test data',
  groups: undefined
]
[ 'The the' ]

[slevithan]

You need to use XRegExp.exec. This will work:

XRegExp.exec('The the test data', repeatedWords).word; // -> 'The'

Or with namespacing:

XRegExp.install('namespacing');
XRegExp.exec('The the test data', repeatedWords).groups.word; // -> 'The'

Ideally XRegExp should be updated in a new major version to have the namespacing feature turned on by default. It should probably also be updated to defer to native handling of named capturing groups in ES2018 browsers/etc. (where native handling was introduced). That way, you could process regexes created by XRegExp with RegExp.prototype.exec (like in your example code) rather than XRegExp.exec and still get the intended result.

[slevithan]

Namespacing is on by default as of #316.

It should probably also be updated to defer to native handling of named capturing groups in ES2018 browsers/etc.

I take this back. Doing so would mean that the same code could give different results in ES2018 and non-ES2018 runtimes.