put router definition into own function

src/main.rs

@@ -167,6 +167,36 @@ fn do_migrations(conn: &mut Connection) -> rusqlite::Result<()> {
     Ok(())
 }
 
+fn app(conn: Connection) -> axum::Router {
+    Router::new()
+        .route("/", get(root))
+        .route("/increase/{id}", post(increase))
+        .route("/decrease/{id}", post(decrease))
+        .route("/set/{id}/to/{amount}", post(set))
+        .layer(
+            TraceLayer::new_for_http().make_span_with(|request: &Request<_>| {
+                let matched_path = request
+                    .extensions()
+                    .get::<MatchedPath>()
+                    .map(MatchedPath::as_str);
+                let request_id = request
+                    .extensions()
+                    .get::<RequestId>()
+                    .map(ToString::to_string)
+                    .unwrap_or_else(|| "unknown".into());
+                info_span!(
+                    "request",
+                    method = ?request.method(),
+                    matched_path,
+                    uri = ?request.uri(),
+                    id = %request_id,
+                )
+            }),
+        )
+        .layer(RequestIdLayer)
+        .with_state(Arc::new(Mutex::new(conn)))
+}
+
 #[tokio::main]
 async fn main() -> Result<(), std::io::Error> {
     tracing_subscriber::registry()
@@ -197,33 +227,7 @@ async fn main() -> Result<(), std::io::Error> {
 
     PreparedStatements::check(&conn).expect("failed to prepare sql statements");
 
-    let app = Router::new()
+    let app = app(conn);
-        .route("/", get(root))
-        .route("/increase/{id}", post(increase))
-        .route("/decrease/{id}", post(decrease))
-        .route("/set/{id}/to/{amount}", post(set))
-        .layer(
-            TraceLayer::new_for_http().make_span_with(|request: &Request<_>| {
-                let matched_path = request
-                    .extensions()
-                    .get::<MatchedPath>()
-                    .map(MatchedPath::as_str);
-                let request_id = request
-                    .extensions()
-                    .get::<RequestId>()
-                    .map(ToString::to_string)
-                    .unwrap_or_else(|| "unknown".into());
-                info_span!(
-                    "request",
-                    method = ?request.method(),
-                    matched_path,
-                    uri = ?request.uri(),
-                    id = %request_id,
-                )
-            }),
-        )
-        .layer(RequestIdLayer)
-        .with_state(Arc::new(Mutex::new(conn)));
 
     let address = "0.0.0.0:3001";
     let listener = tokio::net::TcpListener::bind(address)