fix(websocket): byte-based caps for pending buffer + inbound WS sizes (WS-05, WS-06)

tests/ws_upgrade_session.rs

@@ -11,7 +11,8 @@ use alkcall::registry::registration::{
 };
 use alkcall::registry::spec::{AccessControl, OperationSpec, OperationType, Visibility};
 use alkhttp::websocket::{
-    frame_channel0_chunk, ChunkAssembler, FrameAssembler, WsClient, WS_MESSAGE_CAP,
+    frame_channel0_chunk, ChunkAssembler, FrameAssembler, WsClient, INBOUND_WS_MESSAGE_CAP,
+    WS_MESSAGE_CAP,
 };
 use std::collections::HashMap;
 use std::sync::Arc;
@@ -579,3 +580,29 @@ async fn services_list_over_channel0_is_access_control_filtered() {
     assert!(!names.contains(&"admin/secret"), "got: {names:?}");
     ws.close().await;
 }
+
+#[tokio::test]
+async fn inbound_message_over_cap_fails_the_connection() {
+    let addr = spawn_ws_server(
+        echo_registry(),
+        provider_with(vec![("tok-1", identity("alice", &[]))]),
+    )
+    .await;
+    let mut ws = WsClient::connect_authorized(&format!("{addr}/alk/channels"), "tok-1")
+        .await
+        .unwrap();
+
+    // One WS binary message larger than INBOUND_WS_MESSAGE_CAP: the
+    // server's explicit max_message_size (WS-06) must fail the
+    // connection instead of accepting it (the byte-adapter boundary is
+    // the chunk header, so the adapter never dissects messages; the WS
+    // library cap is the enforcement point).
+    let oversized = vec![b'x'; INBOUND_WS_MESSAGE_CAP + 1];
+    ws.send_binary_piece(&oversized).await;
+
+    let close = ws
+        .next_close(std::time::Duration::from_secs(5))
+        .await
+        .expect("server must fail the oversized-inbound connection (WS-06)");
+    assert!(close.is_some(), "expected a close or stream end, got {close:?}");
+}