From f49a0b8de28d2ac0f96f800cb1353aab853d1a89 Mon Sep 17 00:00:00 2001
From: Nikolay Kim <fafhrd91@gmail.com>
Date: Fri, 17 Sep 2021 10:40:13 +0600
Subject: [PATCH] Simplify fn_transform

---
 ntex-service/CHANGES.md          |  4 ++
 ntex-service/Cargo.toml          |  2 +-
 ntex-service/src/fn_transform.rs | 96 ++++----------------------------
 ntex-service/src/transform.rs    |  3 +-
 4 files changed, 17 insertions(+), 88 deletions(-)

diff --git a/ntex-service/CHANGES.md b/ntex-service/CHANGES.md
index 573a9068..7d8f82a5 100644
--- a/ntex-service/CHANGES.md
+++ b/ntex-service/CHANGES.md
@@ -1,5 +1,9 @@
 # Changes
 
+## [0.2.1] - 2021-09-17
+
+* Simplify fn_transform
+
 ## [0.2.0] - 2021-09-15
 
 * Refactor Transform trait
diff --git a/ntex-service/Cargo.toml b/ntex-service/Cargo.toml
index ccf93926..7dc4cb9e 100644
--- a/ntex-service/Cargo.toml
+++ b/ntex-service/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "ntex-service"
-version = "0.2.0"
+version = "0.2.1"
 authors = ["ntex contributors <team@ntex.rs>"]
 description = "ntex service"
 keywords = ["network", "framework", "async", "futures"]
diff --git a/ntex-service/src/fn_transform.rs b/ntex-service/src/fn_transform.rs
index 781d7330..99fc1196 100644
--- a/ntex-service/src/fn_transform.rs
+++ b/ntex-service/src/fn_transform.rs
@@ -1,101 +1,25 @@
-use std::{future::Future, marker::PhantomData};
-
-use crate::{apply_fn, dev::Apply, Service, Transform};
+use crate::Transform;
 
 /// Use function as transform service
-pub fn fn_transform<S, F, R, Req, Res, Err>(f: F) -> FnTransform<S, F, R, Req, Res, Err>
-where
-    S: Service<Error = Err>,
-    F: Fn(Req, &S) -> R + Clone,
-    R: Future<Output = Result<Res, Err>>,
-{
-    FnTransform::new(f)
+pub fn fn_transform<F>(f: F) -> FnTransform<F> {
+    FnTransform(f)
 }
 
-pub struct FnTransform<S, F, R, Req, Res, Err>
-where
-    S: Service<Error = Err>,
-    F: Fn(Req, &S) -> R + Clone,
-    R: Future<Output = Result<Res, Err>>,
-{
-    f: F,
-    _t: PhantomData<(S, R, Req)>,
-}
+pub struct FnTransform<F>(F);
 
-impl<S, F, R, Req, Res, Err> FnTransform<S, F, R, Req, Res, Err>
+impl<S, F, Out> Transform<S> for FnTransform<F>
 where
-    S: Service<Error = Err>,
-    F: Fn(Req, &S) -> R + Clone,
-    R: Future<Output = Result<Res, Err>>,
+    F: Fn(S) -> Out,
 {
-    fn new(f: F) -> Self {
-        FnTransform { f, _t: PhantomData }
-    }
-}
-
-impl<S, F, R, Req, Res, Err> Transform<S> for FnTransform<S, F, R, Req, Res, Err>
-where
-    S: Service<Error = Err>,
-    F: Fn(Req, &S) -> R + Clone,
-    R: Future<Output = Result<Res, Err>>,
-{
-    type Service = Apply<S, F, R, Req, Res, Err>;
+    type Service = Out;
 
     fn new_transform(&self, service: S) -> Self::Service {
-        apply_fn(service, self.f.clone())
+        (self.0)(service)
     }
 }
 
-impl<S, F, R, Req, Res, Err> Clone for FnTransform<S, F, R, Req, Res, Err>
-where
-    S: Service<Error = Err>,
-    F: Fn(Req, &S) -> R + Clone,
-    R: Future<Output = Result<Res, Err>>,
-{
+impl<F: Clone> Clone for FnTransform<F> {
     fn clone(&self) -> Self {
-        Self::new(self.f.clone())
-    }
-}
-
-#[cfg(test)]
-#[allow(clippy::redundant_clone)]
-mod tests {
-    use ntex_util::future::{lazy, Ready};
-    use std::task::{Context, Poll};
-
-    use super::*;
-    use crate::Service;
-
-    #[derive(Clone)]
-    struct Srv;
-
-    impl Service for Srv {
-        type Request = usize;
-        type Response = usize;
-        type Error = ();
-        type Future = Ready<usize, ()>;
-
-        fn poll_ready(&self, _: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-            Poll::Ready(Ok(()))
-        }
-
-        fn call(&self, i: usize) -> Self::Future {
-            Ready::Ok(i * 2)
-        }
-    }
-
-    #[ntex::test]
-    async fn transform() {
-        let srv = fn_transform(|i: usize, srv: &Srv| srv.call(i + 1)).new_transform(Srv);
-
-        let res = srv.call(10usize).await;
-        assert!(res.is_ok());
-        assert_eq!(res.unwrap(), 22);
-
-        let res = lazy(|cx| srv.poll_ready(cx)).await;
-        assert_eq!(res, Poll::Ready(Ok(())));
-
-        let res = lazy(|cx| srv.poll_shutdown(cx, true)).await;
-        assert_eq!(res, Poll::Ready(()));
+        Self(self.0.clone())
     }
 }
diff --git a/ntex-service/src/transform.rs b/ntex-service/src/transform.rs
index 25f9727b..54d865cd 100644
--- a/ntex-service/src/transform.rs
+++ b/ntex-service/src/transform.rs
@@ -81,7 +81,7 @@ where
 /// ```
 pub trait Transform<S> {
     /// The `TransformService` value created by this factory
-    type Service: Service;
+    type Service;
 
     /// Creates and returns a new Transform component, asynchronously
     fn new_transform(&self, service: S) -> Self::Service;
@@ -122,6 +122,7 @@ impl<T, S> ServiceFactory for ApplyTransform<T, S>
 where
     S: ServiceFactory,
     T: Transform<S::Service>,
+    T::Service: Service,
 {
     type Request = <T::Service as Service>::Request;
     type Response = <T::Service as Service>::Response;