axumguardcombinator

This library lets you write logical (OR, AND) combinators inside Tower Service Layers in Axum servers, which extract the given type T which implement Guard and checks the value of Type T against the input value inside the layer's combinator. Here's a struct which always evaluates to true. ```rust

[derive(Clone,Copy,Debug,PartialEq)]

pub struct Always;

impl Guard for Always {
    fn check_guard(&self,_:&Self) -> bool {
        true
    }
}
#[async_trait::async_trait]
impl<B:Send+Sync> FromRequest<B> for Always {
    type Rejection = ();

    async fn from_request(req: &mut RequestParts<B>) -> Result<Self, Self::Rejection> {
        Ok(Self)
    }
}

Here's a test case combining said struct with a struct that always evaluates to false rust #[tokio::test] async fn testorhappy_path() { let app = Router::new() .route("/",get(ok .layer(GuardLayer::with(Always.or(Never))))); let response = app .oneshot( Request::builder() .uri("/") .body(Body::empty()) .unwrap(), ) .await .unwrap();

    assert_eq!(response.status(), StatusCode::OK);
}

You can nest your combinators to arbitrary depths rust #[tokio::test] async fn testhappynested() { let app = Router::new() .route("/",get(ok .layer(GuardLayer::with( Never.or( Always.and( Always.or( Never))))))); let response = app .oneshot( Request::builder() .uri("/") .body(Body::empty()) .unwrap(), ) .await .unwrap();

    assert_eq!(response.status(), StatusCode::OK);
}

You can input data in the layer which will be evaluated in the Guard impl's check_guard method rust

[derive(Clone,Debug,PartialEq)]

pub struct ArbitraryData{
    data:String,
}
impl Guard for ArbitraryData{
    fn check_guard(&self, expected: &Self) -> bool {
        *self == *expected
    }
}
#[async_trait::async_trait]
impl<B:Send+Sync> FromRequest<B> for ArbitraryData {
    type Rejection = ();

    async fn from_request(req: &mut RequestParts<B>) -> Result<Self, Self::Rejection> {
        Ok(Self{
            data: req.headers().get("data").unwrap()
                .to_str().unwrap().to_string()
        })
    }
}

#[tokio::test] async fn testorhappypathwith_data() { let app = Router::new() .route("/",get(ok .layer(GuardLayer::with(ArbitraryData{ data:String::from("Hello World.") })))); let response = app .oneshot( Request::builder() .uri("/") .header("data","Hello World.") .body(Body::empty()) .unwrap(), ) .await .unwrap();

    assert_eq!(response.status(), StatusCode::OK);
}

```