TypeScript encounters difficulties in parsing named groups within regular expressions

Recently, I encountered an issue with a code snippet that involves regex. Here's the specific line:

regex = /^(?<aa>[0-9]{2})-(?<bb>[0-9]{6})-(?<cc>[0-9]{6})-(?<d>[0-9])$/;

The problem arose when typescript (or perhaps webpack) raised a complaint:

Module parse failed: Error parsing regular expression: Invalid regular expression: /^(?<aa>[0-9]{2})-(?<bb>[0-9]{6})-(?<cc>[0-9]{6})-(?<d>[0-9])$/: Invalid group (18:23)
    You may need an appropriate loader to handle this file type.

It appears that the issue lies with the named groups in the regex pattern. Interestingly, this regex is perfectly valid in JavaScript.

For your reference, I am using typescript version 2.9.2

I have a strong preference for employing named groups. Any suggestions on how I can ensure they compile successfully?

Answer №1

It seems that the regular expression you provided is not valid for JavaScript, as confirmed by , Firefox, and Edge browsers.

However, support for named groups has been introduced in ES2018, so its functionality may vary depending on the browser being used.

To check compatibility, refer to .

The error is likely arising from your webpack module loader rather than the Typescript compiler. One possible solution could be setting the target to ES2018.

For more insights, consider looking into the answer regarding array destructuring on Named capturing groups in JavaScript regex?.

Answer №2

Unfortunately, Typescript does not have built-in support for transpiling regular expressions. For more information, check out issue #24531.

If you are also using Babel in your build process, you may want to consider using the

plugin-transform-named-capturing-groups-regex
plugin.

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