Following breaking changes like `/` vs `//` handling

It is unclear to me how to understand and follow certain breaking behavioral changes or where I would approach finding documentation or resources on the topic.

As far as I understand, before around 29/Nov/2018:02:00:00 +0000 urls like would hit the origin as notice the // vs /. Reviewing the handling of these calls, it’s clear that nothing changed in the request route from our clients to orgins, however CF is in the middle. Now, the same url is not re-written.

So, am I correct that this change in request handling was a change to handling at Cloudflare? I notice that worker preview does seems to retain the old behavior, oddly.
Are there release notes for Cloudflare updates?
Is there a place that documents Cloudflare’s behavior thoroughly including things like this?

Edit: answer - 2018/11/29 Workers Runtime Release Notes

Hi @casey,

This was a mistake on my part.

I made the change to stop automatically collapsing // into /. The previous behavior was clearly a bug (it violated the relevant specs) and multiple customers requested that we fix it.

However, we never should have made such a change without having a plan in place for workers that might be relying on the behavior. We are usually very careful about changes that could affect worker behavior negatively, but in this case I messed up and didn’t think hard enough.

It is our goal that this never happen. We should never push a release that breaks existing workers. You should not have to monitor our change announcements to be safe.

We’ll be improving our processes so that this doesn’t happen again. We’re working on a much more robust testing strategy that will automatically test customers’ workers against the new version before it goes live, and abort the release on any change in behavior. Until that is ready, we’ll place a moratorium on changes that could affect worker behavior negatively, even if they are fixing a bug.


Hey @KentonVarda ,

I really appreciate your reply. It’s worth admitting I was overly frustrated at the time I posted. It was also an unfortunate accident on my part. Thankfully workers provided an incredibly simple and fast fix for the issue.
Regardless, thank you for posting release notes - I wish I had searched here before posting. Workers seem to me more transparent than other CF products.