add test for returning App from function

src/app.rs

@@ -706,4 +706,25 @@ mod tests {
         let body = read_body(resp).await;
         assert_eq!(body, Bytes::from_static(b"https://youtube.com/watch/12345"));
     }
+
+    /// compile-only test for returning app type from function
+    pub fn foreign_app_type() -> App<
+        impl ServiceFactory<
+            ServiceRequest,
+            Response = ServiceResponse<impl MessageBody>,
+            Config = (),
+            InitError = (),
+            Error = Error,
+        >,
+    > {
+        App::new()
+            // logger can be removed without affecting the return type
+            .wrap(crate::middleware::Logger::default())
+            .route("/", web::to(|| async { "hello" }))
+    }
+
+    #[test]
+    fn return_foreign_app_type() {
+        let _app = foreign_app_type();
+    }
 }

tests/test_server.rs

@@ -10,8 +10,13 @@ use std::{
     task::{Context, Poll},
 };
 
-use actix_http::header::{
+use actix_web::{
+    dev::BodyEncoding,
+    http::header::{
         ContentEncoding, ACCEPT_ENCODING, CONTENT_ENCODING, CONTENT_LENGTH, TRANSFER_ENCODING,
+    },
+    middleware::{Compress, NormalizePath, TrailingSlash},
+    web, App, Error, HttpResponse,
 };
 use brotli2::write::{BrotliDecoder, BrotliEncoder};
 use bytes::Bytes;
@@ -31,10 +36,6 @@ use openssl::{
 use rand::{distributions::Alphanumeric, Rng};
 use zstd::stream::{read::Decoder as ZstdDecoder, write::Encoder as ZstdEncoder};
 
-use actix_web::dev::BodyEncoding;
-use actix_web::middleware::{Compress, NormalizePath, TrailingSlash};
-use actix_web::{web, App, Error, HttpResponse};
-
 const STR: &str = "Hello World Hello World Hello World Hello World Hello World \
                    Hello World Hello World Hello World Hello World Hello World \
                    Hello World Hello World Hello World Hello World Hello World \