Handling trailing slashes for directories

[mversic]

Feature Request

I'm willing to implement this if approved

Motivation

I want to support only non-trailing slash paths. To do this I wrap my router with NormalizePathLayer::trim_trailing_slash().layer. This however doesn't work well with ServeDir which will always redirect to a trailing slash path for directories (/kita -> /kita/). Therefore, it's not possible not to have trailing slashes on paths that correspond to directories.

Proposal

There are 3 possibilities on how to handle paths without a trailing slash for directories:

1. redirect to trailing slash
2. return index.html (200)
3. respond with 404 (not found)

I think an enum of 3 variants should be offered with current behavior (redirect) as the default. Additionally, I think that the 3rd variant would make the append_index_html_on_directories deprecated as it would have the same effect

Alternatives

A solution where I would rewrite URL in a layer before this service would have to access filesystem to verify that path corresponds to a directory. This would incur unnecessary IO reads so it would be best to handle it directly within ServeDir

I'm eager to hear other proposals on how to design this API

[jplatte]

I want to support only non-trailing slash paths.

You know that NormalizePath is for supporting both, but without having to check for both variants in routing, right? If you want to send the client a redirect on trailing slash for your non-ServeDir routes, and you are using axum, there is route_with_tsr in axum-extra for this.

[mversic]

I want to support only non-trailing slash paths.

You know that NormalizePath is for supporting both, but without having to check for both variants in routing, right? If you want to send the client a redirect on trailing slash for your non-ServeDir routes, and you are using axum, there is route_with_tsr in axum-extra for this.

My bad. I want to support both paths (with and without a trailing slash). This is currently not possible with ServeDir for directories

[jplatte]

Okay.. So what does your routing setup look like? I would recommend you try to split it into the pieces where the NormalizePath layer makes sense, and those where it doesn't.

[mversic]

Okay.. So what does your routing setup look like? I would recommend you try to split it into the pieces where the NormalizePath layer makes sense, and those where it doesn't.

I just want to serve directories under no-slash paths

My intention was to serve only paths without trailing slashes and have trailing slash redirect to no slash (opposite of what ServeDir does). This is what tanstack router does, it's configurable in astro, etc. In other words it's quite a common request. I would have been ok with either that or serving both (and using canonical href). However, I can't do either with ServeDir because it is hardcoded to redirect non-slash to slash. I want to serve /kita/index.html under the path /kita (not /kita/).

I have already forked this repository and patched ServeDir to suit my needs. Now I would like to get this into tower-http

[jplatte]

Ah, now I understand.

Feel free to send a PR, it sounds like it's going to be a pretty simple one.

[cocoliliace]

Hii @mversic I see that you already have a working version on your fork for 8 months. You said you wanted to merge it into upstream but have not opened a PR. Is there anything I can help? Looks like it's just missing tests and docs now?

Or do we need to introduce a new config option in impl ServeDir, something like redirect_to_path_with_slash and default it to true, and only apply the new logic when it's false, so users who currently use the redirect don't get a breaking change? It might be confusing with NormalizePath though.

[mversic]

Hi @cocoliliace, I wanted a discussion on how to make the best. It could be a breaking change but it doesn't have to.

tbh, I don't remember whether the changes I did back then were just a quick hack for my issue or not. From the looks of it, it was the former so somebody should implement this properly. atm, I'm not sure I have the time on my hands rn, but anything is possible

[cocoliliace]

It looked like a quick hack to me on first glance too but on second thought users who prefer to only serve paths with a trailing slash can just use NormalizePath::append_trailing_slash so I thought maybe it's not too far off?

Anyway I don't really need this feature anymore since I had replaced the thing I was building with nginx, so sorry I probably won't help with this in the near future either even though I said otherwise in the previous comment. I might be up for it if I end up needing this feature again though!