fix: remove trailing / from nested paths

[0xf09f95b4]

Hi!

This PR attempts to fix #134.

Currently, API documentation for nested routes is built by combining the path of the base route (with trailing slashes removed) with the path of the nested route.

If a path of a nested route is only "/", as seen in the todo list example, this leads to that path now containing a trailing slash:

ApiRouter::new().nest_api_service("/todo", ApiRouter::new().api_route("/",post_with(handler, docs)))

Generates this path:

"paths": {
    "/todo/": {
        ...
    },
    ...
}

This PR fixes this issue by removing any trailing slahes after the nested path is built in the nest and nest_api_service functions.

One edge case needs to be handled. In a construct like the following:

ApiRouter::new().nest_api_service("/", ApiRouter::new().api_route("/",post_with(handler, docs)))

the path of this route would be empty. A route of just / is therefore returned unmodified.

I've also added a basic unit test.

This seems to be a simple fix, I hope I didn't miss any other cases here.

[JakkuSakura]

This is called URL normalization. It's better to have a fn normalize(&mut String) for all the trims scattered around the crate. There are a few crates for this purpose, but I prefer the simple or builtin approach.

[0xf09f95b4]

Cool to see that you took over maintainer duties for this crate. Thank you.

I pushed a new variant of this fix, this time basing it directly on the function that Axum uses for the same route calculation. See this function in path_router.rs.

I don't think this is necessarily standard URL normalization: We don't want to remove trailing slashes everywhere, just in this one specific instance. Thanks to your comment, I did find a flaw with my previous implementation and I reflected that realization in an extended test:

• if we nest /test with / we want to get /test
• if we nest /test with /bar we want to get /test/bar
• BUT if we nest /test with /bar/ we want to get /test/bar/, with a trailing slash.

I also removed the previous test that uses / as a base for nesting, this was officially disallowed in Axum with tokio-rs/axum#3051.

[JakkuSakura]

LGTM

[jplatte]

A test showing that nesting under /app/ works as expected would be nice, but the implementation looks solid already. 👍🏼