feat: add path normalization that removes any trailing slashes

Cargo.toml

@@ -15,7 +15,7 @@ tokio = { version = "1.36.0", features = ["full"] }
 axum = "0.7.4"
 hyper = "1.1.0"
 tower = { version = "0.4.13", features = []}
-tower-http = { version = "0.5.1", features = ["trace", "timeout", "request-id", "cors"] }
+tower-http = { version = "0.5.1", features = ["trace", "timeout", "request-id", "cors", "normalize-path"] }
 
 sqlx = { version = "0.7.3", features = ["postgres", "runtime-tokio-rustls", "macros", "migrate", "chrono", "json", "uuid"] }
 

src/lib.rs

@@ -37,8 +37,13 @@ pub fn router(cfg: Config, db: Db) -> Router {
     // Default value is 15 seconds.
     let timeout_layer = middleware::timeout_layer();
 
+    // Any trailing slashes from request paths will be removed. For example, a request with `/foo/`
+    // will be changed to `/foo` before reaching the inner service.
+    let normalize_path_layer = middleware::normalize_path_layer();
+
     Router::new()
         .merge(routes::router())
+        .layer(normalize_path_layer)
         .layer(cors_layer)
         .layer(timeout_layer)
         .layer(propagate_request_id_layer)

src/middleware.rs

@@ -4,6 +4,7 @@ use axum::http::HeaderName;
 use hyper::Request;
 use tower_http::{
     cors::{AllowHeaders, Any, CorsLayer},
+    normalize_path::NormalizePathLayer,
     request_id::{MakeRequestId, PropagateRequestIdLayer, RequestId, SetRequestIdLayer},
     timeout::TimeoutLayer,
 };
@@ -50,3 +51,11 @@ pub fn cors_layer() -> CorsLayer {
 pub fn timeout_layer() -> TimeoutLayer {
     TimeoutLayer::new(Duration::from_secs(15))
 }
+
+/// Middleware that normalizes paths.
+///
+/// Any trailing slashes from request paths will be removed. For example, a request with `/foo/`
+/// will be changed to `/foo` before reaching the inner service.
+pub fn normalize_path_layer() -> NormalizePathLayer {
+    NormalizePathLayer::trim_trailing_slash()
+}