Routing doesn't work for two non-overlapping routes

[Thomasdezeeuw]

Expected Behavior

I expect the following code two produce two distinct routes:

use std::net::SocketAddr;

use actix_web::{web, App, HttpServer, Responder};

#[actix_web::main]
async fn main() {
    let address: SocketAddr = "127.0.0.1:8080".parse().unwrap();

    let server = HttpServer::new(move || {
        App::new().service(
            web::scope("/api/v0").service(
                web::scope("/collection")
                    // FIXME: this routing doesn't work.
                    // NOTE: switching these two routes doesn't work.
                    .route("/{uuid}", web::get().to(by_uuid))
                    .route("/user/{user_name}/{unqualified_id}", web::get().to(by_id)),
            ),
        )
    })
    .bind(address)
    .unwrap();

    println!("http://{}", address);
    server.run().await.unwrap();
}

pub async fn by_uuid(uuid: web::Path<String>) -> impl Responder {
    format!("by UUID: {}", uuid)
}

pub async fn by_id(
    user_name: web::Path<String>,
    unqualified_id: web::Path<String>,
) -> impl Responder {
    format!("by id: {}/{}", user_name, unqualified_id)
}

Current Behavior

However collection/user/{user_name}/{id} route doesn't work:

$ curl 127.0.0.1:8080/api/v0/collection/abc
by UUID: abc                              # Expected
$ curl 127.0.0.1:8080/api/v0/collection/user/USER/ID
wrong number of parameters: 2 expected 1  # Unexpected

It seem Actix is routing the request to the uuid route and hitting an error.

Steps to Reproduce (for bugs)

1. Run the code above.
2. Run curl 127.0.0.1:8080/api/v0/collection/abc, all good.
3. Run curl 127.0.0.1:8080/api/v0/collection/user/USER/ID, hits an error.

Your Environment

• Actix Web Version: 4.0.0-beta.8

[Thomasdezeeuw]

So the issue is just closed without any comment?

[robjtede]

converted to discussion

[Thomasdezeeuw]

... but it's still an issue. Why is closed as an issue?

[robjtede]

i don't know... refresh?

[robjtede]

Routes are matches in the order they are declared, so you'll always match the {uuid} route in this case.

from web::resource docs:

By default, each segment matches the regular expression [^{}/]+.

You can also specify a custom regex in the form {identifier:regex}:

[Thomasdezeeuw]

So it's not possible at all to create these two routes using Actix?

[robjtede]

routes swapped to more specific one first and use one Path extractor with tuple

use std::net::SocketAddr;

use actix_web::{web, App, HttpServer, Responder};

#[actix_web::main]
async fn main() {
    let address: SocketAddr = "127.0.0.1:8080".parse().unwrap();

    let server = HttpServer::new(move || {
        App::new().service(
            web::scope("/api/v0").service(
                web::scope("/collection")
                    .route("/user/{user_name}/{unqualified_id}", web::get().to(by_id))
                    .route("/{uuid}", web::get().to(by_uuid))
            ),
        )
    })
    .bind(address)
    .unwrap();

    println!("http://{}", address);
    server.run().await.unwrap();
}

pub async fn by_uuid(uuid: web::Path<String>) -> impl Responder {
    format!("by UUID: {}", uuid)
}

pub async fn by_id(
    path: web::Path<(String, String)>,
) -> impl Responder {
    let (user_name, unqualified_id) = path.into_inner();
    format!("by id: {}/{}", user_name, unqualified_id)
}

// alternative:

// #[derive(serde::Deserialize)]
// struct ByIdPath {
//     user_name: String,
//     unqualified_id: String,
// }

// pub async fn by_id(
//     path: web::Path<ByIdPath>,
// ) -> impl Responder {
//     format!("by id: {}/{}", &path.user_name, &path.unqualified_id)
// }

[Thomasdezeeuw]

This works! The Path deserialize error: wrong number of parameters: 2 expected 1 was misleading me, thinking the routes were conflicting. The change from user_name: web::Path<String>, unqualified_id: web::Path<String> to path: web::Path<(String, String)> did the trick.

Thanks @robjtede I appreciate your time!

[robjtede]

An alternative using path matching regexes. Assuming you want to only match UUIDs.

App::new().service(
    web::scope("/api/v0").service(
        web::scope("/collection")
        .route("/{uuid:[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}}", web::get().to(by_uuid))
        .route("/user/{user_name}/{unqualified_id}", web::get().to(by_id)),
    ),
)