Bug in twing@5.1.1 causing npm run larva to throw a fatal when viewing patterns

[jameswburke]

Summary

Twing, the JavaScript library used to parse Twig templates in the @penskemediacorp/twig-to-php-parser package was recently updated with a 5.1.1 version.

Steps to Reproduce

1. From within any /assets/ directory for a Larva install, run npm install and npm run larva.
2. Open localhost:3000
3. Navigate to any module, component, or object in the navigation.
4. Twing 5.1.1 will throw the following error,

Cannot render template! 

TwingErrorRuntime: An exception has been thrown during the rendering of a template ("Cannot read property 'toString' of undefined") in "/Users/[name]/vvv-local/www/[project]/public_html/wp-content/themes/[themeName]/assets/node_modules/@penskemediacorp/larva-patterns/base.html" at line 51.

5. Run npm install twing@5.1.0 and run through the remaining steps again to confirm the regression.

Docs

Here's an issue filed in the Twing repo in Gitlab, https://gitlab.com/nightlycommit/twing/-/issues/521.