fix(guard): preserve actor ready timeout retries

Author: NathanFlurry

engine/packages/guard-core/src/utils.rs

@@ -226,7 +226,9 @@ pub(crate) fn should_retry_request(res: &Result<Response<ResponseBody>>) -> bool
 	}
 }
 
-// Determine if a response should trigger a retry: 503 + x-rivet-error
+// Determine if a response should trigger a retry. Guard-specific actor startup
+// failures, including guard.actor_ready_timeout, are signaled as 503 with
+// x-rivet-error and should be retried against a freshly resolved target.
 pub(crate) fn should_retry_request_inner(status: StatusCode, headers: &hyper::HeaderMap) -> bool {
 	status == StatusCode::SERVICE_UNAVAILABLE && headers.contains_key(X_RIVET_ERROR)
 }
@@ -294,3 +296,7 @@ pub(crate) fn to_hyper_close(frame: Option<CloseFrame>) -> hyper_tungstenite::tu
 		))
 	}
 }
+
+#[cfg(test)]
+#[path = "utils/tests.rs"]
+mod tests;

engine/packages/guard-core/src/utils/tests.rs

@@ -0,0 +1,35 @@
+use hyper::header::HeaderValue;
+
+use super::*;
+
+#[test]
+fn retries_guard_actor_ready_timeout_response() {
+	let mut headers = hyper::HeaderMap::new();
+	headers.insert(
+		X_RIVET_ERROR,
+		HeaderValue::from_static("guard.actor_ready_timeout"),
+	);
+
+	assert!(should_retry_request_inner(
+		StatusCode::SERVICE_UNAVAILABLE,
+		&headers,
+	));
+}
+
+#[test]
+fn skips_service_unavailable_without_rivet_error_header() {
+	let headers = hyper::HeaderMap::new();
+
+	assert!(!should_retry_request_inner(
+		StatusCode::SERVICE_UNAVAILABLE,
+		&headers,
+	));
+}
+
+#[test]
+fn skips_non_service_unavailable_with_rivet_error_header() {
+	let mut headers = hyper::HeaderMap::new();
+	headers.insert(X_RIVET_ERROR, HeaderValue::from_static("guard.no_route"));
+
+	assert!(!should_retry_request_inner(StatusCode::NOT_FOUND, &headers));
+}