Now it works correctly with react router

src/main.rs

@@ -1,5 +1,10 @@
+use std::path::Path;
+
 use actix_files;
-use actix_web::{App, HttpServer};
+use actix_web::{
+    dev::{ServiceRequest, ServiceResponse},
+    App, HttpServer,
+};
 use clap::{arg, command, Parser};
 
 #[derive(Parser, Debug)]
@@ -28,10 +33,29 @@ async fn main() -> std::io::Result<()> {
     let bind_addr = format!("{}:{}", args.host, args.port);
     println!("Listening on http://{}", bind_addr);
 
+    let index_path = Path::new(args.serve_dir.as_str())
+        .join(args.index_file.as_str())
+        .display()
+        .to_string();
+
+    let mount_point = args.mount.clone();
+
     HttpServer::new(move || {
-        App::new().default_service(
-            actix_files::Files::new(&args.mount, args.serve_dir.as_str())
-                .index_file(args.index_file.as_str()),
+        let index_path = index_path.to_owned();
+
+        App::new().service(
+            actix_files::Files::new(&mount_point, args.serve_dir.as_str())
+                .index_file(args.index_file.as_str())
+                .default_handler(move |req: ServiceRequest| {
+                    let (http_req, _payload) = req.into_parts();
+                    let index_path = index_path.to_owned();
+
+                    async {
+                        let response =
+                            actix_files::NamedFile::open(index_path)?.into_response(&http_req);
+                        Ok(ServiceResponse::new(http_req, response))
+                    }
+                }),
         )
     })
     .bind(bind_addr)?