1 use std::cell::RefCell;
2 use std::fmt;
3 use std::future::Future;
4 use std::marker::PhantomData;
5 use std::rc::Rc;
6 
7 use actix_http::body::{Body, MessageBody};
8 use actix_http::{Extensions, Request};
9 use actix_service::boxed::{self, BoxServiceFactory};
10 use actix_service::{
11     apply, apply_fn_factory, IntoServiceFactory, ServiceFactory, ServiceFactoryExt, Transform,
12 };
13 use futures_util::future::FutureExt as _;
14 
15 use crate::app_service::{AppEntry, AppInit, AppRoutingFactory};
16 use crate::config::ServiceConfig;
17 use crate::data::{Data, DataFactory, FnDataFactory};
18 use crate::dev::ResourceDef;
19 use crate::error::Error;
20 use crate::resource::Resource;
21 use crate::route::Route;
22 use crate::service::{
23     AppServiceFactory, HttpServiceFactory, ServiceFactoryWrapper, ServiceRequest,
24     ServiceResponse,
25 };
26 
27 type HttpNewService = BoxServiceFactory<(), ServiceRequest, ServiceResponse, Error, ()>;
28 
29 /// Application builder - structure that follows the builder pattern
30 /// for building application instances.
31 pub struct App<T, B> {
32     endpoint: T,
33     services: Vec<Box<dyn AppServiceFactory>>,
34     default: Option<Rc<HttpNewService>>,
35     factory_ref: Rc<RefCell<Option<AppRoutingFactory>>>,
36     data_factories: Vec<FnDataFactory>,
37     external: Vec<ResourceDef>,
38     extensions: Extensions,
39     _phantom: PhantomData<B>,
40 }
41 
42 impl App<AppEntry, Body> {
43     /// Create application builder. Application can be configured with a builder-like pattern.
44     #[allow(clippy::new_without_default)]
new() -> Self45     pub fn new() -> Self {
46         let factory_ref = Rc::new(RefCell::new(None));
47 
48         App {
49             endpoint: AppEntry::new(factory_ref.clone()),
50             data_factories: Vec::new(),
51             services: Vec::new(),
52             default: None,
53             factory_ref,
54             external: Vec::new(),
55             extensions: Extensions::new(),
56             _phantom: PhantomData,
57         }
58     }
59 }
60 
61 impl<T, B> App<T, B>
62 where
63     B: MessageBody,
64     T: ServiceFactory<
65         ServiceRequest,
66         Config = (),
67         Response = ServiceResponse<B>,
68         Error = Error,
69         InitError = (),
70     >,
71 {
72     /// Set application (root level) data.
73     ///
74     /// Application data stored with `App::app_data()` method is available through the
75     /// [`HttpRequest::app_data`](crate::HttpRequest::app_data) method at runtime.
76     ///
77     /// # [`Data<T>`]
78     /// Any [`Data<T>`] type added here can utilize it's extractor implementation in handlers.
79     /// Types not wrapped in `Data<T>` cannot use this extractor. See [its docs](Data<T>) for more
80     /// about its usage and patterns.
81     ///
82     /// ```
83     /// use std::cell::Cell;
84     /// use actix_web::{web, App, HttpRequest, HttpResponse, Responder};
85     ///
86     /// struct MyData {
87     ///     count: std::cell::Cell<usize>,
88     /// }
89     ///
90     /// async fn handler(req: HttpRequest, counter: web::Data<MyData>) -> impl Responder {
91     ///     // note this cannot use the Data<T> extractor because it was not added with it
92     ///     let incr = *req.app_data::<usize>().unwrap();
93     ///     assert_eq!(incr, 3);
94     ///
95     ///     // update counter using other value from app data
96     ///     counter.count.set(counter.count.get() + incr);
97     ///
98     ///     HttpResponse::Ok().body(counter.count.get().to_string())
99     /// }
100     ///
101     /// let app = App::new().service(
102     ///     web::resource("/")
103     ///         .app_data(3usize)
104     ///         .app_data(web::Data::new(MyData { count: Default::default() }))
105     ///         .route(web::get().to(handler))
106     /// );
107     /// ```
108     ///
109     /// # Shared Mutable State
110     /// [`HttpServer::new`](crate::HttpServer::new) accepts an application factory rather than an
111     /// application instance; the factory closure is called on each worker thread independently.
112     /// Therefore, if you want to share a data object between different workers, a shareable object
113     /// needs to be created first, outside the `HttpServer::new` closure and cloned into it.
114     /// [`Data<T>`] is an example of such a sharable object.
115     ///
116     /// ```ignore
117     /// let counter = web::Data::new(AppStateWithCounter {
118     ///     counter: Mutex::new(0),
119     /// });
120     ///
121     /// HttpServer::new(move || {
122     ///     // move counter object into the closure and clone for each worker
123     ///
124     ///     App::new()
125     ///         .app_data(counter.clone())
126     ///         .route("/", web::get().to(handler))
127     /// })
128     /// ```
app_data<U: 'static>(mut self, ext: U) -> Self129     pub fn app_data<U: 'static>(mut self, ext: U) -> Self {
130         self.extensions.insert(ext);
131         self
132     }
133 
134     /// Add application (root) data after wrapping in `Data<T>`.
135     ///
136     /// Deprecated in favor of [`app_data`](Self::app_data).
137     #[deprecated(since = "4.0.0", note = "Use `.app_data(Data::new(val))` instead.")]
data<U: 'static>(self, data: U) -> Self138     pub fn data<U: 'static>(self, data: U) -> Self {
139         self.app_data(Data::new(data))
140     }
141 
142     /// Add application data factory. This function is similar to `.data()` but it accepts a
143     /// "data factory". Data values are constructed asynchronously during application
144     /// initialization, before the server starts accepting requests.
145     #[deprecated(
146         since = "4.0.0",
147         note = "Construct data value before starting server and use `.app_data(Data::new(val))` instead."
148     )]
data_factory<F, Out, D, E>(mut self, data: F) -> Self where F: Fn() -> Out + 'static, Out: Future<Output = Result<D, E>> + 'static, D: 'static, E: std::fmt::Debug,149     pub fn data_factory<F, Out, D, E>(mut self, data: F) -> Self
150     where
151         F: Fn() -> Out + 'static,
152         Out: Future<Output = Result<D, E>> + 'static,
153         D: 'static,
154         E: std::fmt::Debug,
155     {
156         self.data_factories.push(Box::new(move || {
157             {
158                 let fut = data();
159                 async move {
160                     match fut.await {
161                         Err(e) => {
162                             log::error!("Can not construct data instance: {:?}", e);
163                             Err(())
164                         }
165                         Ok(data) => {
166                             let data: Box<dyn DataFactory> = Box::new(Data::new(data));
167                             Ok(data)
168                         }
169                     }
170                 }
171             }
172             .boxed_local()
173         }));
174         self
175     }
176 
177     /// Run external configuration as part of the application building
178     /// process
179     ///
180     /// This function is useful for moving parts of configuration to a
181     /// different module or even library. For example,
182     /// some of the resource's configuration could be moved to different module.
183     ///
184     /// ```
185     /// use actix_web::{web, App, HttpResponse};
186     ///
187     /// // this function could be located in different module
188     /// fn config(cfg: &mut web::ServiceConfig) {
189     ///     cfg.service(web::resource("/test")
190     ///         .route(web::get().to(|| HttpResponse::Ok()))
191     ///         .route(web::head().to(|| HttpResponse::MethodNotAllowed()))
192     ///     );
193     /// }
194     ///
195     /// App::new()
196     ///     .configure(config)  // <- register resources
197     ///     .route("/index.html", web::get().to(|| HttpResponse::Ok()));
198     /// ```
configure<F>(mut self, f: F) -> Self where F: FnOnce(&mut ServiceConfig),199     pub fn configure<F>(mut self, f: F) -> Self
200     where
201         F: FnOnce(&mut ServiceConfig),
202     {
203         let mut cfg = ServiceConfig::new();
204         f(&mut cfg);
205         self.services.extend(cfg.services);
206         self.external.extend(cfg.external);
207         self.extensions.extend(cfg.app_data);
208         self
209     }
210 
211     /// Configure route for a specific path.
212     ///
213     /// This is a simplified version of the `App::service()` method.
214     /// This method can be used multiple times with same path, in that case
215     /// multiple resources with one route would be registered for same resource path.
216     ///
217     /// ```
218     /// use actix_web::{web, App, HttpResponse};
219     ///
220     /// async fn index(data: web::Path<(String, String)>) -> &'static str {
221     ///     "Welcome!"
222     /// }
223     ///
224     /// fn main() {
225     ///     let app = App::new()
226     ///         .route("/test1", web::get().to(index))
227     ///         .route("/test2", web::post().to(|| HttpResponse::MethodNotAllowed()));
228     /// }
229     /// ```
route(self, path: &str, mut route: Route) -> Self230     pub fn route(self, path: &str, mut route: Route) -> Self {
231         self.service(
232             Resource::new(path)
233                 .add_guards(route.take_guards())
234                 .route(route),
235         )
236     }
237 
238     /// Register HTTP service.
239     ///
240     /// Http service is any type that implements `HttpServiceFactory` trait.
241     ///
242     /// Actix Web provides several services implementations:
243     ///
244     /// * *Resource* is an entry in resource table which corresponds to requested URL.
245     /// * *Scope* is a set of resources with common root path.
246     /// * "StaticFiles" is a service for static files support
service<F>(mut self, factory: F) -> Self where F: HttpServiceFactory + 'static,247     pub fn service<F>(mut self, factory: F) -> Self
248     where
249         F: HttpServiceFactory + 'static,
250     {
251         self.services
252             .push(Box::new(ServiceFactoryWrapper::new(factory)));
253         self
254     }
255 
256     /// Default service to be used if no matching resource could be found.
257     ///
258     /// It is possible to use services like `Resource`, `Route`.
259     ///
260     /// ```
261     /// use actix_web::{web, App, HttpResponse};
262     ///
263     /// async fn index() -> &'static str {
264     ///     "Welcome!"
265     /// }
266     ///
267     /// fn main() {
268     ///     let app = App::new()
269     ///         .service(
270     ///             web::resource("/index.html").route(web::get().to(index)))
271     ///         .default_service(
272     ///             web::route().to(|| HttpResponse::NotFound()));
273     /// }
274     /// ```
275     ///
276     /// It is also possible to use static files as default service.
277     ///
278     /// ```
279     /// use actix_web::{web, App, HttpResponse};
280     ///
281     /// fn main() {
282     ///     let app = App::new()
283     ///         .service(
284     ///             web::resource("/index.html").to(|| HttpResponse::Ok()))
285     ///         .default_service(
286     ///             web::to(|| HttpResponse::NotFound())
287     ///         );
288     /// }
289     /// ```
default_service<F, U>(mut self, f: F) -> Self where F: IntoServiceFactory<U, ServiceRequest>, U: ServiceFactory< ServiceRequest, Config = (), Response = ServiceResponse, Error = Error, > + 'static, U::InitError: fmt::Debug,290     pub fn default_service<F, U>(mut self, f: F) -> Self
291     where
292         F: IntoServiceFactory<U, ServiceRequest>,
293         U: ServiceFactory<
294                 ServiceRequest,
295                 Config = (),
296                 Response = ServiceResponse,
297                 Error = Error,
298             > + 'static,
299         U::InitError: fmt::Debug,
300     {
301         // create and configure default resource
302         self.default = Some(Rc::new(boxed::factory(f.into_factory().map_init_err(
303             |e| log::error!("Can not construct default service: {:?}", e),
304         ))));
305 
306         self
307     }
308 
309     /// Register an external resource.
310     ///
311     /// External resources are useful for URL generation purposes only
312     /// and are never considered for matching at request time. Calls to
313     /// `HttpRequest::url_for()` will work as expected.
314     ///
315     /// ```
316     /// use actix_web::{web, App, HttpRequest, HttpResponse, Result};
317     ///
318     /// async fn index(req: HttpRequest) -> Result<HttpResponse> {
319     ///     let url = req.url_for("youtube", &["asdlkjqme"])?;
320     ///     assert_eq!(url.as_str(), "https://youtube.com/watch/asdlkjqme");
321     ///     Ok(HttpResponse::Ok().into())
322     /// }
323     ///
324     /// fn main() {
325     ///     let app = App::new()
326     ///         .service(web::resource("/index.html").route(
327     ///             web::get().to(index)))
328     ///         .external_resource("youtube", "https://youtube.com/watch/{video_id}");
329     /// }
330     /// ```
external_resource<N, U>(mut self, name: N, url: U) -> Self where N: AsRef<str>, U: AsRef<str>,331     pub fn external_resource<N, U>(mut self, name: N, url: U) -> Self
332     where
333         N: AsRef<str>,
334         U: AsRef<str>,
335     {
336         let mut rdef = ResourceDef::new(url.as_ref());
337         *rdef.name_mut() = name.as_ref().to_string();
338         self.external.push(rdef);
339         self
340     }
341 
342     /// Registers middleware, in the form of a middleware component (type),
343     /// that runs during inbound and/or outbound processing in the request
344     /// life-cycle (request -> response), modifying request/response as
345     /// necessary, across all requests managed by the *Application*.
346     ///
347     /// Use middleware when you need to read or modify *every* request or
348     /// response in some way.
349     ///
350     /// Notice that the keyword for registering middleware is `wrap`. As you
351     /// register middleware using `wrap` in the App builder,  imagine wrapping
352     /// layers around an inner App.  The first middleware layer exposed to a
353     /// Request is the outermost layer-- the *last* registered in
354     /// the builder chain.  Consequently, the *first* middleware registered
355     /// in the builder chain is the *last* to execute during request processing.
356     ///
357     /// ```
358     /// use actix_service::Service;
359     /// use actix_web::{middleware, web, App};
360     /// use actix_web::http::{header::CONTENT_TYPE, HeaderValue};
361     ///
362     /// async fn index() -> &'static str {
363     ///     "Welcome!"
364     /// }
365     ///
366     /// fn main() {
367     ///     let app = App::new()
368     ///         .wrap(middleware::Logger::default())
369     ///         .route("/index.html", web::get().to(index));
370     /// }
371     /// ```
wrap<M, B1>( self, mw: M, ) -> App< impl ServiceFactory< ServiceRequest, Config = (), Response = ServiceResponse<B1>, Error = Error, InitError = (), >, B1, > where M: Transform< T::Service, ServiceRequest, Response = ServiceResponse<B1>, Error = Error, InitError = (), >, B1: MessageBody,372     pub fn wrap<M, B1>(
373         self,
374         mw: M,
375     ) -> App<
376         impl ServiceFactory<
377             ServiceRequest,
378             Config = (),
379             Response = ServiceResponse<B1>,
380             Error = Error,
381             InitError = (),
382         >,
383         B1,
384     >
385     where
386         M: Transform<
387             T::Service,
388             ServiceRequest,
389             Response = ServiceResponse<B1>,
390             Error = Error,
391             InitError = (),
392         >,
393         B1: MessageBody,
394     {
395         App {
396             endpoint: apply(mw, self.endpoint),
397             data_factories: self.data_factories,
398             services: self.services,
399             default: self.default,
400             factory_ref: self.factory_ref,
401             external: self.external,
402             extensions: self.extensions,
403             _phantom: PhantomData,
404         }
405     }
406 
407     /// Registers middleware, in the form of a closure, that runs during inbound
408     /// and/or outbound processing in the request life-cycle (request -> response),
409     /// modifying request/response as necessary, across all requests managed by
410     /// the *Application*.
411     ///
412     /// Use middleware when you need to read or modify *every* request or response in some way.
413     ///
414     /// ```
415     /// use actix_service::Service;
416     /// use actix_web::{web, App};
417     /// use actix_web::http::{header::CONTENT_TYPE, HeaderValue};
418     ///
419     /// async fn index() -> &'static str {
420     ///     "Welcome!"
421     /// }
422     ///
423     /// fn main() {
424     ///     let app = App::new()
425     ///         .wrap_fn(|req, srv| {
426     ///             let fut = srv.call(req);
427     ///             async {
428     ///                 let mut res = fut.await?;
429     ///                 res.headers_mut().insert(
430     ///                    CONTENT_TYPE, HeaderValue::from_static("text/plain"),
431     ///                 );
432     ///                 Ok(res)
433     ///             }
434     ///         })
435     ///         .route("/index.html", web::get().to(index));
436     /// }
437     /// ```
wrap_fn<B1, F, R>( self, mw: F, ) -> App< impl ServiceFactory< ServiceRequest, Config = (), Response = ServiceResponse<B1>, Error = Error, InitError = (), >, B1, > where B1: MessageBody, F: Fn(ServiceRequest, &T::Service) -> R + Clone, R: Future<Output = Result<ServiceResponse<B1>, Error>>,438     pub fn wrap_fn<B1, F, R>(
439         self,
440         mw: F,
441     ) -> App<
442         impl ServiceFactory<
443             ServiceRequest,
444             Config = (),
445             Response = ServiceResponse<B1>,
446             Error = Error,
447             InitError = (),
448         >,
449         B1,
450     >
451     where
452         B1: MessageBody,
453         F: Fn(ServiceRequest, &T::Service) -> R + Clone,
454         R: Future<Output = Result<ServiceResponse<B1>, Error>>,
455     {
456         App {
457             endpoint: apply_fn_factory(self.endpoint, mw),
458             data_factories: self.data_factories,
459             services: self.services,
460             default: self.default,
461             factory_ref: self.factory_ref,
462             external: self.external,
463             extensions: self.extensions,
464             _phantom: PhantomData,
465         }
466     }
467 }
468 
469 impl<T, B> IntoServiceFactory<AppInit<T, B>, Request> for App<T, B>
470 where
471     B: MessageBody,
472     T: ServiceFactory<
473         ServiceRequest,
474         Config = (),
475         Response = ServiceResponse<B>,
476         Error = Error,
477         InitError = (),
478     >,
479     T::Future: 'static,
480 {
into_factory(self) -> AppInit<T, B>481     fn into_factory(self) -> AppInit<T, B> {
482         AppInit {
483             async_data_factories: self.data_factories.into_boxed_slice().into(),
484             endpoint: self.endpoint,
485             services: Rc::new(RefCell::new(self.services)),
486             external: RefCell::new(self.external),
487             default: self.default,
488             factory_ref: self.factory_ref,
489             extensions: RefCell::new(Some(self.extensions)),
490         }
491     }
492 }
493 
494 #[cfg(test)]
495 mod tests {
496     use actix_service::Service;
497     use actix_utils::future::{err, ok};
498     use bytes::Bytes;
499 
500     use super::*;
501     use crate::http::{header, HeaderValue, Method, StatusCode};
502     use crate::middleware::DefaultHeaders;
503     use crate::service::ServiceRequest;
504     use crate::test::{call_service, init_service, read_body, try_init_service, TestRequest};
505     use crate::{web, HttpRequest, HttpResponse};
506 
507     #[actix_rt::test]
test_default_resource()508     async fn test_default_resource() {
509         let srv =
510             init_service(App::new().service(web::resource("/test").to(HttpResponse::Ok))).await;
511         let req = TestRequest::with_uri("/test").to_request();
512         let resp = srv.call(req).await.unwrap();
513         assert_eq!(resp.status(), StatusCode::OK);
514 
515         let req = TestRequest::with_uri("/blah").to_request();
516         let resp = srv.call(req).await.unwrap();
517         assert_eq!(resp.status(), StatusCode::NOT_FOUND);
518 
519         let srv = init_service(
520             App::new()
521                 .service(web::resource("/test").to(HttpResponse::Ok))
522                 .service(
523                     web::resource("/test2")
524                         .default_service(|r: ServiceRequest| {
525                             ok(r.into_response(HttpResponse::Created()))
526                         })
527                         .route(web::get().to(HttpResponse::Ok)),
528                 )
529                 .default_service(|r: ServiceRequest| {
530                     ok(r.into_response(HttpResponse::MethodNotAllowed()))
531                 }),
532         )
533         .await;
534 
535         let req = TestRequest::with_uri("/blah").to_request();
536         let resp = srv.call(req).await.unwrap();
537         assert_eq!(resp.status(), StatusCode::METHOD_NOT_ALLOWED);
538 
539         let req = TestRequest::with_uri("/test2").to_request();
540         let resp = srv.call(req).await.unwrap();
541         assert_eq!(resp.status(), StatusCode::OK);
542 
543         let req = TestRequest::with_uri("/test2")
544             .method(Method::POST)
545             .to_request();
546         let resp = srv.call(req).await.unwrap();
547         assert_eq!(resp.status(), StatusCode::CREATED);
548     }
549 
550     // allow deprecated App::data
551     #[allow(deprecated)]
552     #[actix_rt::test]
test_data_factory()553     async fn test_data_factory() {
554         let srv = init_service(
555             App::new()
556                 .data_factory(|| ok::<_, ()>(10usize))
557                 .service(web::resource("/").to(|_: web::Data<usize>| HttpResponse::Ok())),
558         )
559         .await;
560         let req = TestRequest::default().to_request();
561         let resp = srv.call(req).await.unwrap();
562         assert_eq!(resp.status(), StatusCode::OK);
563 
564         let srv = init_service(
565             App::new()
566                 .data_factory(|| ok::<_, ()>(10u32))
567                 .service(web::resource("/").to(|_: web::Data<usize>| HttpResponse::Ok())),
568         )
569         .await;
570         let req = TestRequest::default().to_request();
571         let resp = srv.call(req).await.unwrap();
572         assert_eq!(resp.status(), StatusCode::INTERNAL_SERVER_ERROR);
573     }
574 
575     // allow deprecated App::data
576     #[allow(deprecated)]
577     #[actix_rt::test]
test_data_factory_errors()578     async fn test_data_factory_errors() {
579         let srv = try_init_service(
580             App::new()
581                 .data_factory(|| err::<u32, _>(()))
582                 .service(web::resource("/").to(|_: web::Data<usize>| HttpResponse::Ok())),
583         )
584         .await;
585 
586         assert!(srv.is_err());
587     }
588 
589     #[actix_rt::test]
test_extension()590     async fn test_extension() {
591         let srv = init_service(App::new().app_data(10usize).service(web::resource("/").to(
592             |req: HttpRequest| {
593                 assert_eq!(*req.app_data::<usize>().unwrap(), 10);
594                 HttpResponse::Ok()
595             },
596         )))
597         .await;
598         let req = TestRequest::default().to_request();
599         let resp = srv.call(req).await.unwrap();
600         assert_eq!(resp.status(), StatusCode::OK);
601     }
602 
603     #[actix_rt::test]
test_wrap()604     async fn test_wrap() {
605         let srv = init_service(
606             App::new()
607                 .wrap(
608                     DefaultHeaders::new()
609                         .header(header::CONTENT_TYPE, HeaderValue::from_static("0001")),
610                 )
611                 .route("/test", web::get().to(HttpResponse::Ok)),
612         )
613         .await;
614         let req = TestRequest::with_uri("/test").to_request();
615         let resp = call_service(&srv, req).await;
616         assert_eq!(resp.status(), StatusCode::OK);
617         assert_eq!(
618             resp.headers().get(header::CONTENT_TYPE).unwrap(),
619             HeaderValue::from_static("0001")
620         );
621     }
622 
623     #[actix_rt::test]
test_router_wrap()624     async fn test_router_wrap() {
625         let srv = init_service(
626             App::new()
627                 .route("/test", web::get().to(HttpResponse::Ok))
628                 .wrap(
629                     DefaultHeaders::new()
630                         .header(header::CONTENT_TYPE, HeaderValue::from_static("0001")),
631                 ),
632         )
633         .await;
634         let req = TestRequest::with_uri("/test").to_request();
635         let resp = call_service(&srv, req).await;
636         assert_eq!(resp.status(), StatusCode::OK);
637         assert_eq!(
638             resp.headers().get(header::CONTENT_TYPE).unwrap(),
639             HeaderValue::from_static("0001")
640         );
641     }
642 
643     #[actix_rt::test]
test_wrap_fn()644     async fn test_wrap_fn() {
645         let srv = init_service(
646             App::new()
647                 .wrap_fn(|req, srv| {
648                     let fut = srv.call(req);
649                     async move {
650                         let mut res = fut.await?;
651                         res.headers_mut()
652                             .insert(header::CONTENT_TYPE, HeaderValue::from_static("0001"));
653                         Ok(res)
654                     }
655                 })
656                 .service(web::resource("/test").to(HttpResponse::Ok)),
657         )
658         .await;
659         let req = TestRequest::with_uri("/test").to_request();
660         let resp = call_service(&srv, req).await;
661         assert_eq!(resp.status(), StatusCode::OK);
662         assert_eq!(
663             resp.headers().get(header::CONTENT_TYPE).unwrap(),
664             HeaderValue::from_static("0001")
665         );
666     }
667 
668     #[actix_rt::test]
test_router_wrap_fn()669     async fn test_router_wrap_fn() {
670         let srv = init_service(
671             App::new()
672                 .route("/test", web::get().to(HttpResponse::Ok))
673                 .wrap_fn(|req, srv| {
674                     let fut = srv.call(req);
675                     async {
676                         let mut res = fut.await?;
677                         res.headers_mut()
678                             .insert(header::CONTENT_TYPE, HeaderValue::from_static("0001"));
679                         Ok(res)
680                     }
681                 }),
682         )
683         .await;
684         let req = TestRequest::with_uri("/test").to_request();
685         let resp = call_service(&srv, req).await;
686         assert_eq!(resp.status(), StatusCode::OK);
687         assert_eq!(
688             resp.headers().get(header::CONTENT_TYPE).unwrap(),
689             HeaderValue::from_static("0001")
690         );
691     }
692 
693     #[actix_rt::test]
test_external_resource()694     async fn test_external_resource() {
695         let srv = init_service(
696             App::new()
697                 .external_resource("youtube", "https://youtube.com/watch/{video_id}")
698                 .route(
699                     "/test",
700                     web::get().to(|req: HttpRequest| {
701                         HttpResponse::Ok()
702                             .body(req.url_for("youtube", &["12345"]).unwrap().to_string())
703                     }),
704                 ),
705         )
706         .await;
707         let req = TestRequest::with_uri("/test").to_request();
708         let resp = call_service(&srv, req).await;
709         assert_eq!(resp.status(), StatusCode::OK);
710         let body = read_body(resp).await;
711         assert_eq!(body, Bytes::from_static(b"https://youtube.com/watch/12345"));
712     }
713 }
714