Picking up new router files

[imbolc]

After creating a new route folder it doesn't pick it up. I'm not sure, if no one else complains, maybe it's something to do with my particular configuration. It's probably some kind of cache, because when I add dbg! to let router = dbg!(FolderRouter::into_router()); the bug disappears.

Really love this overall, thank you 🙏

[tristandruyen]

Thanks for reporting this! Caching can indeed be tricky...
To help me investigate & reproduce this:

• A minimal code snippet that reproduces the issue would be extremely helpful. (ideally including tree output of the directory structure it belongs to)
• Any unusual project structure or build configurations? Are you using a workspace ?
• Are you seeing the issue in an upstream tool like cargo-watch, or plain cargo run/build ?

[imbolc]

git clone git@github.com:vault81/axum-folder-router.git
cd axum-folder-router

cargo run --example simple
curl -s -o /dev/null -w "%{http_code}" http://localhost:3000/
# 200
curl -s -o /dev/null -w "%{http_code}" http://localhost:3000/foo
# 404

# Create a new route
mkdir examples/simple/api/foo
echo 'pub async fn get() {}' >examples/simple/api/foo/route.rs

# Restart the server

# The new route doesn't work
curl -s -o /dev/null -w "%{http_code}" http://localhost:3000/foo
# 404

# Stop the server
cargo clean
# Start the server

# Now the new route works
curl -s -o /dev/null -w "%{http_code}" http://localhost:3000/foo
# 200

[imbolc]

For now I'm using this build.rs:

fn main() {
    // This makes cargo rebuild on each run, to pick up new routes
    // TODO: remove after the axum-folder-router issue is resolved:
    // https://github.com/vault81/axum-folder-router/issues/2
    println!("cargo:rerun-if-changed=a-non-existing-file");
}

[imbolc]

I added this print:

#[proc_macro_attribute]
pub fn folder_router(attr: TokenStream, item: TokenStream) -> TokenStream {
    println!("running folder_router macro");

and found that the macro does run if I touch an existing route, but it doesn't if I add a new one. I'm guessing it's because Cargo is watching these paths and not the whole routes folder:

#[path = "/data/0/lab/axum-folder-router/./examples/simple/api"]
mod __folder_router__myfolderrouter____examples_simple_api {
    #[path = "route.rs"]

This build.rs seems to rebuild optimally:

fn main() {
    // Watches axum-folder-router routes folder, so it can pick up new routes
    println!(
        "cargo:rerun-if-changed={routes_folder}",
        routes_folder = "examples/simple/api"
    );
}

It doesn't seem to be a better solution until stabilization of the nightly proc_macro::tracked_path. So I guess all we can do for now is to mention the build.rs in the docs.

[tristandruyen]

Thanks for the PR & pointer to proc_macro::tracked_path. I'll try to add a feature-gated fix so it works on nightly OOTB. (#4)