1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236

//! For middleware documentation, see [`Compat`].

use std::{
    future::Future,
    pin::Pin,
    task::{Context, Poll},
};

use futures_core::{future::LocalBoxFuture, ready};
use pin_project_lite::pin_project;

use crate::{
    body::{BoxBody, MessageBody},
    dev::{Service, Transform},
    error::Error,
    service::ServiceResponse,
};

/// Middleware for enabling any middleware to be used in [`Resource::wrap`](crate::Resource::wrap),
/// and [`Condition`](super::Condition).
///
/// # Examples
/// ```
/// use actix_web::middleware::{Logger, Compat};
/// use actix_web::{App, web};
///
/// let logger = Logger::default();
///
/// // this would not compile because of incompatible body types
/// // let app = App::new()
/// //     .service(web::scope("scoped").wrap(logger));
///
/// // by using this middleware we can use the logger on a scope
/// let app = App::new()
///     .service(web::scope("scoped").wrap(Compat::new(logger)));
/// ```
pub struct Compat<T> {
    transform: T,
}

#[cfg(test)]
impl Compat<super::Noop> {
    pub(crate) fn noop() -> Self {
        Self {
            transform: super::Noop,
        }
    }
}

impl<T> Compat<T> {
    /// Wrap a middleware to give it broader compatibility.
    pub fn new(middleware: T) -> Self {
        Self {
            transform: middleware,
        }
    }
}

impl<S, T, Req> Transform<S, Req> for Compat<T>
where
    S: Service<Req>,
    T: Transform<S, Req>,
    T::Future: 'static,
    T::Response: MapServiceResponseBody,
    T::Error: Into<Error>,
{
    type Response = ServiceResponse<BoxBody>;
    type Error = Error;
    type Transform = CompatMiddleware<T::Transform>;
    type InitError = T::InitError;
    type Future = LocalBoxFuture<'static, Result<Self::Transform, Self::InitError>>;

    fn new_transform(&self, service: S) -> Self::Future {
        let fut = self.transform.new_transform(service);
        Box::pin(async move {
            let service = fut.await?;
            Ok(CompatMiddleware { service })
        })
    }
}

pub struct CompatMiddleware<S> {
    service: S,
}

impl<S, Req> Service<Req> for CompatMiddleware<S>
where
    S: Service<Req>,
    S::Response: MapServiceResponseBody,
    S::Error: Into<Error>,
{
    type Response = ServiceResponse<BoxBody>;
    type Error = Error;
    type Future = CompatMiddlewareFuture<S::Future>;

    actix_service::forward_ready!(service);

    fn call(&self, req: Req) -> Self::Future {
        let fut = self.service.call(req);
        CompatMiddlewareFuture { fut }
    }
}

pin_project! {
    pub struct CompatMiddlewareFuture<Fut> {
        #[pin]
        fut: Fut,
    }
}

impl<Fut, T, E> Future for CompatMiddlewareFuture<Fut>
where
    Fut: Future<Output = Result<T, E>>,
    T: MapServiceResponseBody,
    E: Into<Error>,
{
    type Output = Result<ServiceResponse<BoxBody>, Error>;

    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
        let res = match ready!(self.project().fut.poll(cx)) {
            Ok(res) => res,
            Err(err) => return Poll::Ready(Err(err.into())),
        };

        Poll::Ready(Ok(res.map_body()))
    }
}

/// Convert `ServiceResponse`'s `ResponseBody<B>` generic type to `ResponseBody<Body>`.
pub trait MapServiceResponseBody {
    fn map_body(self) -> ServiceResponse<BoxBody>;
}

impl<B> MapServiceResponseBody for ServiceResponse<B>
where
    B: MessageBody + 'static,
{
    #[inline]
    fn map_body(self) -> ServiceResponse<BoxBody> {
        self.map_into_boxed_body()
    }
}

#[cfg(test)]
mod tests {
    // easier to code when cookies feature is disabled
    #![allow(unused_imports)]

    use actix_service::IntoService;

    use super::*;
    use crate::{
        dev::ServiceRequest,
        http::StatusCode,
        middleware::{self, Condition, Logger},
        test::{self, call_service, init_service, TestRequest},
        web, App, HttpResponse,
    };

    #[actix_rt::test]
    #[cfg(all(feature = "cookies", feature = "__compress"))]
    async fn test_scope_middleware() {
        use crate::middleware::Compress;

        let logger = Logger::default();
        let compress = Compress::default();

        let srv = init_service(
            App::new().service(
                web::scope("app")
                    .wrap(logger)
                    .wrap(Compat::new(compress))
                    .service(web::resource("/test").route(web::get().to(HttpResponse::Ok))),
            ),
        )
        .await;

        let req = TestRequest::with_uri("/app/test").to_request();
        let resp = call_service(&srv, req).await;
        assert_eq!(resp.status(), StatusCode::OK);
    }

    #[actix_rt::test]
    #[cfg(all(feature = "cookies", feature = "__compress"))]
    async fn test_resource_scope_middleware() {
        use crate::middleware::Compress;

        let logger = Logger::default();
        let compress = Compress::default();

        let srv = init_service(
            App::new().service(
                web::resource("app/test")
                    .wrap(Compat::new(logger))
                    .wrap(Compat::new(compress))
                    .route(web::get().to(HttpResponse::Ok)),
            ),
        )
        .await;

        let req = TestRequest::with_uri("/app/test").to_request();
        let resp = call_service(&srv, req).await;
        assert_eq!(resp.status(), StatusCode::OK);
    }

    #[actix_rt::test]
    async fn test_condition_scope_middleware() {
        let srv = |req: ServiceRequest| {
            Box::pin(
                async move { Ok(req.into_response(HttpResponse::InternalServerError().finish())) },
            )
        };

        let logger = Logger::default();

        let mw = Condition::new(true, Compat::new(logger))
            .new_transform(srv.into_service())
            .await
            .unwrap();
        let resp = call_service(&mw, TestRequest::default().to_srv_request()).await;
        assert_eq!(resp.status(), StatusCode::INTERNAL_SERVER_ERROR);
    }

    #[actix_rt::test]
    async fn compat_noop_is_noop() {
        let srv = test::ok_service();

        let mw = Compat::noop()
            .new_transform(srv.into_service())
            .await
            .unwrap();

        let resp = call_service(&mw, TestRequest::default().to_srv_request()).await;
        assert_eq!(resp.status(), StatusCode::OK);
    }
}