update readme, add success and failure case instructions

README.md

@@ -6,10 +6,18 @@ data upon initial return from Stripe, but if you manually enter the URL, it work
 
 # How to run
 
-First, run `cargo run --bin=stripe &`; this will start the "Stripe" service listening on
-localhost:4001. Then, run `cargo run --bin=princess` and visit http://localhost:4000/ and click the
+In order to demonstrate the issue, the "stripe" service must be run on a different origin than the
+"princess" service. The following will set that up:
+
+`cargo run --bin=stripe & cargo run --bin=princess -- http://$(hostname):4001/`
+
+Now visit http://localhost:4000/ and click the
 buttons. At the end, you'll end up at a page at http://localhost:4000/success and see the test data
-inserted in the initial get of `/`.
+inserted in the initial get of `/`, or a message indicating failure. To see it succeed, run:
+
+`cargo run --bin=stripe & cargo run --bin=princess`
+
+and follow the buttons starting from http://localhost:4000/ again to the end.
 
 # Why is it called "princess"?
 

src/bin/princess.rs

@@ -51,19 +51,25 @@ pub async fn post_slash(session: Session) -> impl IntoResponse {
     session.insert(&SIGNUP_KEY, user).await.unwrap();
     session.save().await.unwrap();
 
-    Redirect::to("http://localhost:4001/").into_response()
+    let mut args = std::env::args();
+    args.next();
+    let stripe = args.next().unwrap_or("http://localhost:4001/".into());
+
+    Redirect::to(&stripe).into_response()
 }
 
 pub async fn success(session: Session) -> impl IntoResponse {
     session.load().await.unwrap();
-    dbg!("loaded the session");
     let user = if let Some(user) = session.get::<TestData>(&SIGNUP_KEY).await.unwrap_or(None) {
-        dbg!("loaded test data");
         user
     } else {
-        dbg!("could not load data from session");
         TestData::default()
     };
+    let user = if user == TestData::default() {
+        "Default TestData, session fetch failed.".to_string()
+    } else {
+        format!("Successful fetch from session: {user:?}")
+    };
     let html: Html<_> = format!("<p>Check out this test data:</p><pre>{user:?}</pre>").into();
     html.into_response()
 }

src/bin/stripe.rs

@@ -12,7 +12,7 @@ async fn main() {
     let app = Router::new()
         .route("/", get(get_slash).post(post_slash))
         .into_make_service();
-    let addr = SocketAddr::from(([127, 0, 0, 1], 4001));
+    let addr = SocketAddr::from(([0, 0, 0, 0], 4001));
     let listener = TcpListener::bind(&addr).await.unwrap();
 
     axum::serve(listener, app).await.unwrap();