Fixed a URL order issue and optimized function for cloudfront

[lockehooper]

Not sure if you still maintain this repo but I recently massively expanded the scope of URLs I was using with it and it started to cause unforeseen issues when deployed to Cloudfront. I noticed that the compute utilization was getting into the 70-100 range, but more importantly I noticed some routes were not getting routed correctly. I believe this is because the routes in the generated function are exactly as they appear in the Next file tree.

This causes a problem is cases such as the following rewrites list:

1. /posts/:postId/:commentId
2. /posts/favorites/:postId
3. /posts/favorites
4. /posts

This list would be generated by an app folder with a posts folder with [:postId] and favorites inside of it, each of those with their own dynamic folder inside them. The issue is that a request to /posts/favorites/:postId would get caught by /posts/:postId/:commentId and cause an error in the browser since the IDs would be invalid.

To address both of these problems I took the rewrites list and turned it into a tree structure where the keys are the possible routes, destinations are marked with $_d and dynamic routes marked with $_p. The tree structure can be injected as a string into the Cloudfront template. I updated that to use the tree structure as well. I noticed the compute utilization in cloudfront is down to the single digits for me since making this change.

I copied the changes I made into a forked version of the repo and will leave them here as a PR. I won't claim they are fully tested, but can say this is what is working for my use case.

[zdenham]

Hi @lockehooper thanks for the PR.

This repo is not actively maintained, and personally I started using https://sst.dev/ rather than my own home-grown solution. That being said, if you bump the package.json version and test a bit I'd be happy to merge and hopefully someone finds it useful. Or can just leave the PR open indefinitely!