add middleware composition tests (#2375)

src/middleware/mod.rs

@@ -19,3 +19,43 @@ mod compress;
 
 #[cfg(feature = "__compress")]
 pub use self::compress::Compress;
+
+#[cfg(test)]
+mod tests {
+    use crate::{http::StatusCode, App};
+
+    use super::*;
+
+    #[test]
+    fn common_combinations() {
+        // ensure there's no reason that the built-in middleware cannot compose
+
+        let _ = App::new()
+            .wrap(Compat::new(Logger::default()))
+            .wrap(Condition::new(true, DefaultHeaders::new()))
+            .wrap(DefaultHeaders::new().header("X-Test2", "X-Value2"))
+            .wrap(ErrorHandlers::new().handler(StatusCode::FORBIDDEN, |res| {
+                Ok(ErrorHandlerResponse::Response(res))
+            }))
+            .wrap(Logger::default())
+            .wrap(NormalizePath::new(TrailingSlash::Trim));
+
+        let _ = App::new()
+            .wrap(NormalizePath::new(TrailingSlash::Trim))
+            .wrap(Logger::default())
+            .wrap(ErrorHandlers::new().handler(StatusCode::FORBIDDEN, |res| {
+                Ok(ErrorHandlerResponse::Response(res))
+            }))
+            .wrap(DefaultHeaders::new().header("X-Test2", "X-Value2"))
+            .wrap(Condition::new(true, DefaultHeaders::new()))
+            .wrap(Compat::new(Logger::default()));
+
+        #[cfg(feature = "__compress")]
+        {
+            let _ = App::new().wrap(Compress::default()).wrap(Logger::default());
+            let _ = App::new().wrap(Logger::default()).wrap(Compress::default());
+            let _ = App::new().wrap(Compat::new(Compress::default()));
+            let _ = App::new().wrap(Condition::new(true, Compat::new(Compress::default())));
+        }
+    }
+}