chore: checkpoint before Python removal

vendor/tower/tests/load_shed/main.rs

@@ -0,0 +1,39 @@
+#![cfg(feature = "load-shed")]
+#[path = "../support.rs"]
+mod support;
+
+use tokio_test::{assert_ready_err, assert_ready_ok, task};
+use tower::load_shed::LoadShedLayer;
+use tower_test::{assert_request_eq, mock};
+
+#[tokio::test(flavor = "current_thread")]
+async fn when_ready() {
+    let _t = support::trace_init();
+
+    let layer = LoadShedLayer::new();
+    let (mut service, mut handle) = mock::spawn_layer(layer);
+
+    assert_ready_ok!(service.poll_ready(), "overload always reports ready");
+
+    let mut response = task::spawn(service.call("hello"));
+
+    assert_request_eq!(handle, "hello").send_response("world");
+    assert_eq!(assert_ready_ok!(response.poll()), "world");
+}
+
+#[tokio::test(flavor = "current_thread")]
+async fn when_not_ready() {
+    let _t = support::trace_init();
+
+    let layer = LoadShedLayer::new();
+    let (mut service, mut handle) = mock::spawn_layer::<_, (), _>(layer);
+
+    handle.allow(0);
+
+    assert_ready_ok!(service.poll_ready(), "overload always reports ready");
+
+    let mut fut = task::spawn(service.call("hello"));
+
+    let err = assert_ready_err!(fut.poll());
+    assert!(err.is::<tower::load_shed::error::Overloaded>());
+}