Function mid_session_encoding_switch_rejected

nodedb/tests/native_protocol.rs:505–554

()

/// response (decode failure). The connection stays open — it is not terminated.
#[tokio::test]
async fn mid_session_encoding_switch_rejected() {
    let server = NativeTestServer::start().await;

    let (mut stream, _ack) = do_handshake(server.addr, &HelloFrame::current())
        .await
        .expect("handshake");

    // First frame: JSON → establishes JSON encoding for the session.
    let ping_json = NativeRequest {
        op: OpCode::Ping,
        seq: 1,
        fields: RequestFields::Text(TextFields::default()),
    };
    let json_bytes = sonic_rs::to_vec(&ping_json).expect("json encode");
    write_frame(&mut stream, &json_bytes).await;

    // Consume the response to the first Ping.
    let _first_resp = tokio::time::timeout(Duration::from_secs(5), read_frame(&mut stream))
        .await
        .expect("timeout")
        .expect("first response");

    // Second frame: MsgPack — the session is locked to JSON, so this must fail decode.
    let ping_mp = NativeRequest {
        op: OpCode::Ping,
        seq: 2,
        fields: RequestFields::Text(TextFields::default()),
    };
    let mp_bytes = zerompk::to_msgpack_vec(&ping_mp).expect("msgpack encode");
    write_frame(&mut stream, &mp_bytes).await;

    let switch_resp = tokio::time::timeout(Duration::from_secs(5), read_frame(&mut stream))
        .await
        .expect("timeout")
        .expect("switch response");

    server.shutdown().await;

    // The response must be JSON-encoded (session is still in JSON mode).
    assert_eq!(
        switch_resp[0], b'{',
        "response must still be JSON after mid-session switch attempt"
    );
    let resp: NativeResponse = sonic_rs::from_slice(&switch_resp).expect("json decode");
    assert_eq!(
        resp.status,
        nodedb_types::protocol::opcodes::ResponseStatus::Error,
        "mid-session encoding switch must produce an Error response"
    );
}