vtcode 0.141.5

A Rust-based terminal coding agent with modular architecture supporting multiple LLM providers
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112

use std::future::Future;
use std::time::Duration;

use anyhow::Result;
use vtcode_ui::tui::app::InlineHandle;

/// Gives the external application exclusive access to the terminal while it runs.
///
/// The guard restores event processing from `Drop`, so cancellation of the
/// surrounding task cannot leave the fullscreen TUI suspended.
pub(crate) async fn run_with_event_loop_suspended<T, F>(
    handle: &InlineHandle,
    suspend_tui: bool,
    launch: F,
) -> Result<T>
where
    F: FnOnce() -> Result<T>,
{
    let guard = TuiSuspensionGuard::new(handle, suspend_tui);
    if guard.is_active() {
        tokio::time::sleep(EVENT_STREAM_STOP_DELAY).await;
        handle.clear_input_queue();
    }

    let result = launch();
    drop(guard);
    result
}

pub(crate) async fn run_with_event_loop_suspended_async<T, F, Fut>(
    handle: &InlineHandle,
    suspend_tui: bool,
    launch: F,
) -> Result<T>
where
    F: FnOnce() -> Fut,
    Fut: Future<Output = Result<T>>,
{
    let guard = TuiSuspensionGuard::new(handle, suspend_tui);
    if guard.is_active() {
        tokio::time::sleep(EVENT_STREAM_STOP_DELAY).await;
        handle.clear_input_queue();
    }

    let result = launch().await;
    drop(guard);
    result
}

const EVENT_STREAM_STOP_DELAY: Duration = Duration::from_millis(150);

struct TuiSuspensionGuard<'a> {
    handle: &'a InlineHandle,
    active: bool,
}

impl<'a> TuiSuspensionGuard<'a> {
    fn new(handle: &'a InlineHandle, active: bool) -> Self {
        if active {
            // Fully stop the background EventStream task so terminal editors
            // have exclusive access to stdin.
            handle.stop_event_stream();
        }
        Self { handle, active }
    }

    fn is_active(&self) -> bool {
        self.active
    }
}

impl Drop for TuiSuspensionGuard<'_> {
    fn drop(&mut self) {
        if self.active {
            self.handle.clear_input_queue();
            self.handle.resume_event_loop();
            self.handle.start_event_stream();
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use tokio::sync::{mpsc, oneshot};
    use vtcode_ui::tui::app::{InlineCommand, InlineHandle};

    #[tokio::test]
    async fn cancellation_restores_suspended_event_loop() {
        let (command_tx, mut command_rx) = mpsc::unbounded_channel();
        let handle = InlineHandle::new_for_tests(command_tx);
        let (started_tx, started_rx) = oneshot::channel();
        let task_handle = handle.clone();
        let task = tokio::spawn(async move {
            run_with_event_loop_suspended_async(&task_handle, true, || async move {
                let _ = started_tx.send(());
                std::future::pending::<Result<()>>().await
            })
            .await
        });

        started_rx.await.expect("launch closure should start");
        task.abort();
        task.await.expect_err("suspended operation should be cancelled");

        assert!(matches!(command_rx.try_recv(), Ok(InlineCommand::StopEventStream)));
        assert!(matches!(command_rx.try_recv(), Ok(InlineCommand::ClearInputQueue)));
        assert!(matches!(command_rx.try_recv(), Ok(InlineCommand::ClearInputQueue)));
        assert!(matches!(command_rx.try_recv(), Ok(InlineCommand::ResumeEventLoop)));
        assert!(matches!(command_rx.try_recv(), Ok(InlineCommand::StartEventStream)));
    }
}