Create middleware to require not being logged in

src/main.rs

 
 use tide::utils::After;
 
+use middleware::*;
+
 mod fs;
 mod middleware;
 mod post;
     tide::log::start();
     let mut app = tide::new();
 
-    app.with(After(middleware::errors));
-    app.with(middleware::session());
+    app.with(After(errors));
+    app.with(session());
 
     app.at("/").get(routes::index);
     app.at("/posts")
-        .with(middleware::require_auth)
+        .with(require_auth)
         .post(routes::create_post);
     app.at("/posts/:id")
         .get(routes::single_post)
         .post(routes::update_post)
         .delete(routes::delete_post);
     app.at("/posts/:id/edit")
-        .with(middleware::require_auth)
+        .with(require_auth)
         .get(routes::edit_post);
-    app.at("/login").get(routes::login_page).post(routes::login);
-    app.at("/logout")
-        .with(middleware::require_auth)
-        .post(routes::logout);
+    app.at("/login")
+        .with(require_guest)
+        .get(routes::login_page)
+        .post(routes::login);
+    app.at("/logout").with(require_auth).post(routes::logout);
 
     app.listen("127.0.0.1:8080").await?;
 

src/middleware.rs

     })
 }
 
+pub fn require_guest<'a>(
+    req: Request<()>,
+    next: Next<'a, ()>,
+) -> Pin<Box<dyn Future<Output = Result> + 'a + Send>> {
+    Box::pin(async {
+        let logged_in: bool = req.session().get("logged_in").unwrap_or(false);
+        if logged_in {
+            Ok(Redirect::new("/").into())
+        } else {
+            Ok(next.run(req).await)
+        }
+    })
+}
+
 pub async fn errors(mut res: Response) -> Result<Response> {
     let mut context = Context::new();
 

src/routes.rs

 }
 
 pub async fn login(mut req: Request<()>) -> Result {
-    let logged_in: bool = req.session().get("logged_in").unwrap_or(false);
-    if logged_in {
-        return Ok(Redirect::new("/").into());
-    }
-
     let username = env::var("ADMIN_USERNAME")?;
     let password = env::var("ADMIN_PASSWORD")?;
     let user: User = req.body_form().await?;