[SOLVED] How can I define Axum routes in sub modules?

How can I define Axum routes in sub modules?

My project is a simple in memory to-do app stolen from a YouTube tutorial, where he defines a router for the specific folder. Structure right now looks like this:

├── Cargo.lock
├── Cargo.toml
└── src
   ├── in_memory
   │  ├── mod.rs
   │  ├── routes.rs
   │  └── state.rs
   └── main.rs

I do not feel comfortable with the functions being used for routes all written in the same file. If I want to make my project bigger and add another section, where should I put all the new code? Am I obliged to use the same file?

Solution

You can definitely split your routes into separate files. You can return Routers from functions configuring your sub routes and then .merge() them in your main file.

src/
- routes/
  - route1.rs
  - route2.rs
- routes.rs
- main.rs

// route1.rs / route2.rs

pub async fn list() -> impl IntoResponse { ... }
  
pub fn get_routes() -> Router {
    Router::new()
        .route("/", get(list))
        // ... other routes
}

// routes.rs

mod route1;
mod route2;

// main.rs

#[tokio::main]
async fn main() -> Result<(), Error> {
    let app = Router::new()       
        .merge(routes::route1::get_routes())
        .merge(routes::route2::get_routes());
    
    run(app).await
}