fix(waku/router): regex in file replacement to correctly handle all matches (fs-router)

[daanlenaerts]

The current fs-router regex, /(^|\/|\\)_([^/]+)_(\/|\\|\.)/g, which is ran during build only replaces the first occurrence of underscores in scenarios where multiple underscore-surrounded segments are separated by single slashes. For example, in the string "app/_propertyId_/_surveyPartKey_.js", only _propertyId_ was being replaced, but _surveyPartKey_ was left unchanged due to the / being consumed during the first match.

This can easily be checked by running the following code:

const file = "app/_propertyId_/_surveyPartKey_.js";
console.log(file.replace(/(^|\/|\\)_([^/]+)_(\/|\\|\.)/g, '$1[$2]$3'));
// app/[propertyId]/_surveyPartKey_.js

Solution

The regex has been updated to /(?<=^|\/|\\)_([^/]+)_(?=\/|\\|\.)/g. This uses positive lookbehind (?<=^|\/|\\) and lookahead (?=\/|\\|\.) assertions to check for preceding and succeeding characters without consuming them. This allows every instance of the pattern to be replaced, regardless of their position in the string.

[vercel]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Updated (UTC)
waku	✅ Ready (Inspect)	Visit Preview	Apr 27, 2024 11:45am

[codesandbox-ci]

This pull request is automatically built and testable in CodeSandbox.

To see build info of the built libraries, click here or the icon next to each commit SHA.

[dai-shi]

Thanks so much for the fix!

[dai-shi]

Wow, nice. I should improve my regex skill.

(We need to avoid this HACK, but if it's not soon, we should probably extract the logic into a function and add a test for it.)

[daanlenaerts]

No worries, thanks for merging it!