path: root/src/server/headless/tests/pane_graphics.rs

use super::*;

fn receive_render(receiver: &std::sync::mpsc::Receiver<Vec<u8>>, timeout: Duration) -> Vec<u8> {
    receiver.recv_timeout(timeout).unwrap()
}

#[tokio::test]
async fn unchanged_retained_graphics_leave_the_committed_surface_and_delivery_untouched() {
    let (mut server, _control_rx, client_rx, pane_id) = retained_test_server_with_control(
        b"populated terminal\r\n\x1b_Ga=T,f=32,t=d,i=7,p=3,s=1,v=1,c=1,r=1,q=2;/wAA/w==\x1b\\",
    );
    let client = server.clients.get_mut(&1).unwrap();
    client.mode = ClientConnectionMode::ClientShell;
    client.cell_size = crate::kitty_graphics::HostCellSize {
        width_px: 10,
        height_px: 20,
    };
    server.render_and_stream();
    let _ = receive_render(&client_rx, Duration::from_millis(100));

    let before = server.clients[&1]
        .render_state
        .last_pane_surface()
        .unwrap()
        .clone();
    assert_eq!(before.graphics.placements.len(), 1);
    assert!(before.graphics.assets.is_empty());
    let cells = server.clients[&1]
        .render_state
        .last_pane_surface()
        .unwrap()
        .frame
        .cells
        .as_ptr();
    let mut hidden = crate::workspace::Workspace::test_new("hidden");
    let hidden_pane = hidden.tabs[0].root_pane;
    hidden.insert_test_runtime(
        hidden_pane,
        crate::terminal::TerminalRuntime::test_with_screen_bytes(80, 24, b"hidden output"),
    );
    server.app.state.workspaces.push(hidden);
    for source in [pane_id, hidden_pane] {
        assert!(server.render_retained_pane_surface_and_stream(&HashSet::from([source])));
        assert!(client_rx.try_recv().is_err());
        let after = server.clients[&1].render_state.last_pane_surface().unwrap();
        assert_eq!(after, &before);
        assert_eq!(after.frame.cells.as_ptr(), cells);
    }

    // Skipping the no-op must not discard the upload cache for the next real update.
    write_shared_test_pane(&mut server, pane_id, b"\x1b[Hchanged");
    assert!(server.render_retained_pane_surface_and_stream(&HashSet::from([pane_id])));
    let ServerMessage::PaneSurface(updated) =
        read_server_message(receive_render(&client_rx, Duration::from_millis(100)))
    else {
        panic!("expected retained image with changed text");
    };
    assert!(updated.graphics.assets.is_empty());
    assert_eq!(updated.graphics.placements, before.graphics.placements);
    assert!(frame_text(&updated.frame).contains("changed"));
}

#[tokio::test]
async fn first_kitty_image_updates_retained_surface_without_full_redraw() {
    let (mut server, _control_rx, client_rx, pane_id) =
        retained_test_server_with_control(b"text before image");
    let client = server.clients.get_mut(&1).unwrap();
    client.mode = ClientConnectionMode::ClientShell;
    client.render_state =
        crate::server::render_stream::ClientRenderState::new(RenderEncoding::SemanticFrame);
    client.cell_size = crate::kitty_graphics::HostCellSize {
        width_px: 10,
        height_px: 20,
    };
    server.render_and_stream();
    let ServerMessage::PaneSurface(initial) =
        read_server_message(receive_render(&client_rx, Duration::from_millis(100)))
    else {
        panic!("expected text-only baseline");
    };
    assert!(initial.graphics.placements.is_empty());

    write_shared_test_pane(
        &mut server,
        pane_id,
        b"\x1b_Ga=T,f=32,t=d,i=7,p=3,s=1,v=1,c=1,r=1,q=2;/wAA/w==\x1b\\",
    );
    assert!(server.render_retained_pane_surface_and_stream(&HashSet::from([pane_id])));
    let ServerMessage::PaneSurface(repainted) =
        read_server_message(receive_render(&client_rx, Duration::from_millis(100)))
    else {
        panic!("expected image update without a full redraw");
    };
    assert_eq!(repainted.graphics.placements.len(), 1);
    assert_eq!(repainted.graphics.assets[0].data, [255, 0, 0, 255]);
    assert_eq!(repainted.panes[0].inner_rect, initial.panes[0].inner_rect);

    // Text changes while an image is visible must reuse its uploaded pixels.
    write_shared_test_pane(&mut server, pane_id, b"\rupdated text");
    assert!(server.render_retained_pane_surface_and_stream(&HashSet::from([pane_id])));
    let ServerMessage::PaneSurface(text_update) =
        read_server_message(receive_render(&client_rx, Duration::from_millis(100)))
    else {
        panic!("expected retained text and image scene");
    };
    assert_eq!(
        text_update.graphics.placements,
        repainted.graphics.placements
    );
    assert!(text_update.graphics.assets.is_empty());
    assert!(frame_text(&text_update.frame).contains("updated text"));

    write_shared_test_pane(&mut server, pane_id, b"\x1b_Ga=d,d=A\x1b\\");
    assert!(server.render_retained_pane_surface_and_stream(&HashSet::from([pane_id])));
    let ServerMessage::PaneSurface(deleted) =
        read_server_message(receive_render(&client_rx, Duration::from_millis(100)))
    else {
        panic!("expected image removal");
    };
    assert!(deleted.graphics.placements.is_empty());
    assert!(deleted.graphics.assets.is_empty());

    write_shared_test_pane(&mut server, pane_id, b"\rtext only again");
    assert!(server.render_retained_pane_surface_and_stream(&HashSet::from([pane_id])));
    assert!(matches!(
        read_server_message(receive_render(&client_rx, Duration::from_millis(100))),
        ServerMessage::PaneSurfacePatch(_)
    ));

    // A full output queue must not mark unsent pixels as delivered.
    fill_render_lane(&server);
    write_shared_test_pane(
        &mut server,
        pane_id,
        b"\x1b_Ga=T,f=32,t=d,i=7,p=3,s=1,v=1,c=1,r=1,q=2;/wAA/w==\x1b\\",
    );
    assert!(server.render_retained_pane_surface_and_stream(&HashSet::from([pane_id])));
    assert!(server.clients[&1]
        .render_state
        .last_pane_surface()
        .unwrap()
        .graphics
        .placements
        .is_empty());
    let _ = receive_render(&client_rx, Duration::from_millis(100));
    server.render_and_stream();
    let ServerMessage::PaneSurface(recovered) =
        read_server_message(receive_render(&client_rx, Duration::from_millis(100)))
    else {
        panic!("expected deferred graphics recovery");
    };
    assert_eq!(recovered.graphics.assets[0].data, [255, 0, 0, 255]);
}

#[tokio::test]
async fn offscreen_images_keep_text_updates_on_the_retained_path() {
    let (mut server, _control_rx, client_rx, pane_id) = retained_test_server_with_control(
        b"\x1b_Ga=T,f=32,t=d,i=7,s=1,v=1,c=1,r=1,q=2;/wAA/w==\x1b\\",
    );
    let client = server.clients.get_mut(&1).unwrap();
    client.mode = ClientConnectionMode::ClientShell;
    client.render_state =
        crate::server::render_stream::ClientRenderState::new(RenderEncoding::SemanticFrame);
    client.cell_size = crate::kitty_graphics::HostCellSize {
        width_px: 10,
        height_px: 20,
    };
    let sources = HashSet::from([pane_id]);
    server.render_and_stream();
    let _ = receive_render(&client_rx, Duration::from_millis(100));

    write_shared_test_pane(&mut server, pane_id, b"\x1b_Ga=d,d=a,q=2\x1b\\");
    assert!(server.render_retained_pane_surface_and_stream(&sources));
    let ServerMessage::PaneSurface(hidden) =
        read_server_message(receive_render(&client_rx, Duration::from_millis(100)))
    else {
        panic!("expected hidden image scene");
    };
    assert!(hidden.graphics.placements.is_empty());
    assert_eq!(hidden.graphics.retained_assets.len(), 1);

    // Clients reject row patches while images are retained, so the text must
    // arrive in a surface that keeps the hidden image without resending it.
    write_shared_test_pane(&mut server, pane_id, b"\rtext while hidden");
    assert!(server.render_retained_pane_surface_and_stream(&sources));
    let ServerMessage::PaneSurface(text_update) =
        read_server_message(receive_render(&client_rx, Duration::from_millis(100)))
    else {
        panic!("expected a surface the client accepts while images are retained");
    };
    assert!(frame_text(&text_update.frame).contains("text while hidden"));
    assert!(text_update.graphics.placements.is_empty());
    assert!(text_update.graphics.assets.is_empty());
    assert_eq!(
        text_update.graphics.retained_assets,
        hidden.graphics.retained_assets
    );

    write_shared_test_pane(&mut server, pane_id, b"\x1b_Ga=p,i=7,c=1,r=1,q=2\x1b\\");
    assert!(server.render_retained_pane_surface_and_stream(&sources));
    let ServerMessage::PaneSurface(shown) =
        read_server_message(receive_render(&client_rx, Duration::from_millis(100)))
    else {
        panic!("expected the hidden image to return");
    };
    assert_eq!(shown.graphics.placements.len(), 1);
    assert!(shown.graphics.assets.is_empty());

    write_shared_test_pane(&mut server, pane_id, b"\x1b_Ga=d,d=a,q=2\x1b\\");
    assert!(server.render_retained_pane_surface_and_stream(&sources));
    let _ = receive_render(&client_rx, Duration::from_millis(100));
    write_shared_test_pane(&mut server, pane_id, b"\x1b_Ga=d,d=I,i=7,q=2\x1b\\");
    assert!(server.render_retained_pane_surface_and_stream(&sources));
    let ServerMessage::PaneSurface(deleted) =
        read_server_message(receive_render(&client_rx, Duration::from_millis(100)))
    else {
        panic!("expected the deleted image to be released");
    };
    assert!(deleted.graphics.retained_assets.is_empty());
}

#[tokio::test]
async fn retained_unicode_image_arrives_after_fragmented_upload_without_reupload() {
    let (mut server, _control_rx, client_rx, pane_id) =
        retained_test_server_with_control(b"\x1b[?1049h");
    let client = server.clients.get_mut(&1).unwrap();
    client.mode = ClientConnectionMode::ClientShell;
    client.cell_size = crate::kitty_graphics::HostCellSize {
        width_px: 10,
        height_px: 20,
    };
    server.render_and_stream();
    let _ = receive_render(&client_rx, Duration::from_millis(100));
    let sources = HashSet::from([pane_id]);
    // Yazi-style virtual placement: uploading the image and drawing its Unicode cell
    // can happen in separate PTY reads, with no text dirty rows when upload completes.
    for bytes in [
        b"\x1b_Ga=t,f=32,t=d,i=1193046,s=1,v=1,q=2;/wAA/w".as_slice(),
        b"==\x1b\\",
        b"\x1b_Ga=p,U=1,i=1193046,c=1,r=1,q=2\x1b\\",
    ] {
        write_shared_test_pane(&mut server, pane_id, bytes);
        assert!(server.render_retained_pane_surface_and_stream(&sources));
        for frame in client_rx.try_iter() {
            if let ServerMessage::PaneSurface(surface) = read_server_message(frame) {
                assert!(surface.graphics.placements.is_empty());
            }
        }
    }
    write_shared_test_pane(
        &mut server,
        pane_id,
        "\x1b[2;3H\x1b[38;2;18;52;86m\u{10eeee}\u{0305}\u{0305}\x1b[0m".as_bytes(),
    );
    assert!(server.render_retained_pane_surface_and_stream(&sources));
    let ServerMessage::PaneSurface(surface) =
        read_server_message(receive_render(&client_rx, Duration::from_millis(100)))
    else {
        panic!("virtual image must arrive without a tab switch");
    };
    assert_eq!(surface.graphics.placements.len(), 1);
    assert_eq!(surface.graphics.assets[0].data, [255, 0, 0, 255]);
    // Retransmission removes placements; recreating the virtual placement must
    // invalidate the delivered asset without needing another text update.
    write_shared_test_pane(
        &mut server,
        pane_id,
        b"\x1b_Ga=t,f=32,t=d,i=1193046,s=1,v=1,q=2;AP8A/w==\x1b\\",
    );
    assert!(server.render_retained_pane_surface_and_stream(&sources));
    let ServerMessage::PaneSurface(removed) =
        read_server_message(receive_render(&client_rx, Duration::from_millis(100)))
    else {
        panic!("retransmission must remove the virtual placement");
    };
    assert!(removed.graphics.placements.is_empty());
    write_shared_test_pane(
        &mut server,
        pane_id,
        b"\x1b_Ga=p,U=1,i=1193046,c=1,r=1,q=2\x1b\\",
    );
    assert!(server.render_retained_pane_surface_and_stream(&sources));
    let ServerMessage::PaneSurface(replaced) =
        read_server_message(receive_render(&client_rx, Duration::from_millis(100)))
    else {
        panic!("updated image pixels must arrive");
    };
    assert_eq!(replaced.graphics.assets[0].data, [0, 255, 0, 255]);
    assert_ne!(
        surface.graphics.assets[0].key,
        replaced.graphics.assets[0].key
    );
}

#[tokio::test]
#[ignore = "manual retained text/image scaling profile"]
async fn render_scale_profile_retained_graphics() {
    use ratatui::layout::Direction;
    for retained in [false, true] {
        for image in ["none", "visible", "offscreen", "unchanged-image"] {
            for count in [1, 15] {
                let (mut server, _control_rx, client_rx, root) =
                    retained_test_server_with_control(b"populated terminal\r\n");
                let mut pane_ids = vec![root];
                for index in 1..count {
                    let workspace = &mut server.app.state.workspaces[0];
                    workspace.tabs[0]
                        .layout
                        .focus_pane(pane_ids[(index - 1) / 2]);
                    let id = workspace.test_split(if index % 2 == 0 {
                        Direction::Vertical
                    } else {
                        Direction::Horizontal
                    });
                    workspace.insert_test_runtime(
                        id,
                        crate::terminal::TerminalRuntime::test_with_screen_bytes(
                            80,
                            24,
                            b"populated terminal\r\n",
                        ),
                    );
                    pane_ids.push(id);
                }
                let client = server.clients.get_mut(&1).unwrap();
                client.mode = ClientConnectionMode::ClientShell;
                client.cell_size = crate::kitty_graphics::HostCellSize {
                    width_px: 10,
                    height_px: 20,
                };
                if image != "none" {
                    write_shared_test_pane(
                        &mut server,
                        root,
                        b"\x1b_Ga=T,f=32,t=d,i=7,p=3,s=1,v=1,c=1,r=1,q=2;/wAA/w==\x1b\\",
                    );
                }
                server.render_and_stream();
                let _ = receive_render(&client_rx, Duration::from_millis(100));
                if image == "offscreen" {
                    write_shared_test_pane(&mut server, root, b"\x1b_Ga=d,d=a,q=2\x1b\\");
                    server.render_and_stream();
                    let _ = receive_render(&client_rx, Duration::from_millis(100));
                }
                let sources = pane_ids.iter().copied().collect();
                let mut samples = Vec::new();
                for sample in 0..110 {
                    if image != "unchanged-image" {
                        for id in &pane_ids {
                            write_shared_test_pane(
                                &mut server,
                                *id,
                                format!("\x1b[H{sample:03}").as_bytes(),
                            );
                        }
                    }
                    let started = Instant::now();
                    if retained {
                        assert!(server.render_retained_pane_surface_and_stream(&sources));
                    } else {
                        server.render_and_stream();
                    }
                    let elapsed = started.elapsed();
                    for frame in client_rx.try_iter() {
                        if let ServerMessage::PaneSurface(surface) = read_server_message(frame) {
                            assert!(surface.graphics.assets.is_empty());
                        }
                    }
                    if sample >= 10 {
                        samples.push(elapsed);
                    }
                }
                samples.sort_unstable();
                println!(
                    "retained={retained} 80x24 panes={count} image={image} median_us={:.3} p95_us={:.3}",
                    samples[50].as_secs_f64() * 1e6,
                    samples[94].as_secs_f64() * 1e6
                );
            }
        }
    }
}

#[tokio::test]
async fn client_shell_surface_projects_terminal_kitty_images_from_authoritative_runtime() {
    let (mut server, _control_rx, client_rx, _pane_id) = retained_test_server_with_control(
        b"\x1b_Ga=T,f=32,t=d,i=7,p=3,s=1,v=1,c=1,r=1,q=2;/wAA/w==\x1b\\",
    );
    let client = server.clients.get_mut(&1).unwrap();
    client.mode = ClientConnectionMode::ClientShell;
    client.render_state =
        crate::server::render_stream::ClientRenderState::new(RenderEncoding::SemanticFrame);
    client.cell_size = crate::kitty_graphics::HostCellSize {
        width_px: 10,
        height_px: 20,
    };

    server.render_and_stream();
    let message = read_server_message(receive_render(&client_rx, Duration::from_millis(100)));
    let ServerMessage::PaneSurface(surface) = message else {
        panic!("expected client shell pane surface");
    };
    assert_eq!(surface.graphics.placements.len(), 1);
    assert_eq!(surface.graphics.assets.len(), 1);
    assert!(matches!(
        surface.graphics.placements[0].asset.source,
        crate::protocol::SurfaceGraphicsSource::Terminal {
            target: crate::protocol::SurfaceGraphicsTarget::Pane { .. },
            image_id: 7,
        }
    ));
    assert_eq!(surface.graphics.assets[0].data, vec![255, 0, 0, 255]);
}

#[tokio::test]
async fn client_shell_delivers_equal_pixels_for_distinct_terminal_image_ids() {
    let (mut server, _control_rx, client_rx, _pane_id) = retained_test_server_with_control(
        b"\x1b_Ga=T,f=32,t=d,i=7,p=3,s=1,v=1,c=1,r=1,q=2;/wAA/w==\x1b\\\x1b_Ga=T,f=32,t=d,i=8,p=4,s=1,v=1,c=1,r=1,q=2;/wAA/w==\x1b\\",
    );
    let client = server.clients.get_mut(&1).unwrap();
    client.mode = ClientConnectionMode::ClientShell;
    client.render_state =
        crate::server::render_stream::ClientRenderState::new(RenderEncoding::SemanticFrame);
    client.cell_size = crate::kitty_graphics::HostCellSize {
        width_px: 10,
        height_px: 20,
    };

    server.render_and_stream();
    let message = read_server_message(receive_render(&client_rx, Duration::from_millis(100)));
    let ServerMessage::PaneSurface(surface) = message else {
        panic!("expected client shell pane surface");
    };
    assert_eq!(surface.graphics.placements.len(), 2);
    assert_eq!(surface.graphics.assets.len(), 2);
    assert_ne!(
        surface.graphics.assets[0].key,
        surface.graphics.assets[1].key
    );
    assert_eq!(
        surface.graphics.assets[0].data,
        surface.graphics.assets[1].data
    );

    server.clients.get_mut(&1).unwrap().request_repaint();
    server.render_and_stream();
    let message = read_server_message(receive_render(&client_rx, Duration::from_millis(100)));
    let ServerMessage::PaneSurface(surface) = message else {
        panic!("expected replacement client shell pane surface");
    };
    assert_eq!(surface.graphics.placements.len(), 2);
    assert!(surface.graphics.assets.is_empty());
}

#[tokio::test]
async fn client_shell_keeps_offscreen_terminal_image_loaded_until_the_image_is_deleted() {
    let (mut server, _control_rx, client_rx, pane) = retained_test_server_with_control(
        b"\x1b_Ga=t,f=32,t=d,i=7,s=1,v=1,q=2;/wAA/w==\x1b\\\x1b_Ga=p,i=7,c=1,r=1,q=2\x1b\\",
    );
    let client = server.clients.get_mut(&1).unwrap();
    client.mode = ClientConnectionMode::ClientShell;
    client.render_state =
        crate::server::render_stream::ClientRenderState::new(RenderEncoding::SemanticFrame);
    client.cell_size = crate::kitty_graphics::HostCellSize {
        width_px: 10,
        height_px: 20,
    };
    let render = |server: &mut HeadlessServer| {
        server.render_and_stream();
        let message = read_server_message(receive_render(&client_rx, Duration::from_millis(100)));
        let ServerMessage::PaneSurface(surface) = message else {
            panic!("expected client shell pane surface");
        };
        surface.graphics
    };

    let shown = render(&mut server);
    assert_eq!(shown.placements.len(), 1);
    assert_eq!(shown.assets.len(), 1);
    let key = shown.assets[0].key.clone();

    // Scrolling an image out of view removes its placement but keeps the image.
    write_shared_test_pane(&mut server, pane, b"\x1b_Ga=d,d=a,q=2\x1b\\");
    let hidden = render(&mut server);
    assert!(hidden.placements.is_empty());
    assert!(hidden.assets.is_empty());
    assert_eq!(hidden.retained_assets, vec![key.clone()]);

    write_shared_test_pane(&mut server, pane, b"\x1b_Ga=p,i=7,c=1,r=1,q=2\x1b\\");
    let returned = render(&mut server);
    assert_eq!(returned.placements.len(), 1);
    assert_eq!(returned.placements[0].asset, key);
    assert!(
        returned.assets.is_empty(),
        "an image the client still holds must not be sent again"
    );

    write_shared_test_pane(&mut server, pane, b"\x1b_Ga=d,d=a,q=2\x1b\\");
    assert_eq!(render(&mut server).retained_assets, vec![key.clone()]);

    // Replacing a hidden image with same-sized pixels releases the stale copy.
    write_shared_test_pane(
        &mut server,
        pane,
        b"\x1b_Ga=t,f=32,t=d,i=7,s=1,v=1,q=2;AAD//w==\x1b\\",
    );
    assert!(render(&mut server).retained_assets.is_empty());
    write_shared_test_pane(&mut server, pane, b"\x1b_Ga=p,i=7,c=1,r=1,q=2\x1b\\");
    let replaced_hidden = render(&mut server);
    assert_eq!(replaced_hidden.assets.len(), 1);
    assert_eq!(replaced_hidden.assets[0].data, vec![0, 0, 255, 255]);
    write_shared_test_pane(&mut server, pane, b"\x1b_Ga=d,d=a,q=2\x1b\\");
    assert_eq!(render(&mut server).retained_assets.len(), 1);

    // Deleting a hidden image releases it on the host.
    write_shared_test_pane(&mut server, pane, b"\x1b_Ga=d,d=I,i=7,q=2\x1b\\");
    let deleted = render(&mut server);
    assert!(deleted.placements.is_empty());
    assert!(deleted.retained_assets.is_empty());

    // Reusing the id for new pixels delivers them instead of the old image.
    write_shared_test_pane(
        &mut server,
        pane,
        b"\x1b_Ga=T,f=32,t=d,i=7,s=1,v=1,c=1,r=1,q=2;AP8A/w==\x1b\\",
    );
    let replaced = render(&mut server);
    assert_eq!(replaced.assets.len(), 1);
    assert_eq!(replaced.assets[0].data, vec![0, 255, 0, 255]);
    assert_ne!(replaced.assets[0].key, key);
}

#[tokio::test]
async fn client_shell_evicts_least_recently_visible_offscreen_terminal_images() {
    let mut screen = Vec::new();
    for image_id in 1..=17 {
        screen.extend_from_slice(
            format!("\x1b_Ga=T,f=32,t=d,i={image_id},s=1,v=1,c=1,r=1,q=2;/wAA/w==\x1b\\")
                .as_bytes(),
        );
    }
    let (mut server, _control_rx, client_rx, pane) = retained_test_server_with_control(&screen);
    let client = server.clients.get_mut(&1).unwrap();
    client.mode = ClientConnectionMode::ClientShell;
    client.render_state =
        crate::server::render_stream::ClientRenderState::new(RenderEncoding::SemanticFrame);
    client.cell_size = crate::kitty_graphics::HostCellSize {
        width_px: 10,
        height_px: 20,
    };
    let render = |server: &mut HeadlessServer| {
        server.render_and_stream();
        let message = read_server_message(receive_render(&client_rx, Duration::from_millis(100)));
        let ServerMessage::PaneSurface(surface) = message else {
            panic!("expected client shell pane surface");
        };
        surface.graphics
    };
    let retained_ids = |graphics: &crate::protocol::SurfaceGraphicsScene| {
        graphics
            .retained_assets
            .iter()
            .map(|key| match key.source {
                crate::protocol::SurfaceGraphicsSource::Terminal { image_id, .. } => image_id,
                _ => panic!("expected terminal image"),
            })
            .collect::<Vec<_>>()
    };
    assert_eq!(render(&mut server).assets.len(), 17);

    write_shared_test_pane(&mut server, pane, b"\x1b_Ga=d,d=a,q=2\x1b\\");
    let hidden = render(&mut server);
    assert!(hidden.placements.is_empty());
    assert_eq!(retained_ids(&hidden), (1..=16).collect::<Vec<_>>());

    // Image 17 was evicted, so showing it sends its pixels again.
    write_shared_test_pane(&mut server, pane, b"\x1b_Ga=p,i=17,c=1,r=1,q=2\x1b\\");
    assert_eq!(render(&mut server).assets.len(), 1);

    // The most recently visible image is kept first; the oldest is evicted.
    write_shared_test_pane(&mut server, pane, b"\x1b_Ga=d,d=a,q=2\x1b\\");
    let rehidden = render(&mut server);
    let mut expected = vec![17];
    expected.extend(1..=15);
    assert_eq!(retained_ids(&rehidden), expected);
}

fn fill_render_lane(server: &HeadlessServer) {
    let queued = HeadlessServer::frame_server_message(&ServerMessage::ReloadSoundConfig)
        .expect("dummy frame");
    server.clients[&1]
        .writer
        .as_ref()
        .unwrap()
        .test_fill_render(queued);
}

#[tokio::test]
async fn pixel_mouse_activation_follows_child_1016_without_graphics_demand() {
    let (mut server, _client_rx, _pane_id) =
        retained_test_server(b"\x1b[?1003h\x1b[?1006h\x1b[?1016h");
    let (writer, control_rx, _render_rx) = test_client_writer();
    let client = server.clients.get_mut(&1).unwrap();
    client.writer = Some(writer);
    client.direct_graphics = false;
    client.pixel_mouse = true;
    client.cell_size = crate::kitty_graphics::HostCellSize {
        width_px: 10,
        height_px: 20,
    };
    client.host_mouse_capture_active = None;
    client.host_sgr_pixels_active = None;

    server.stream_host_mouse_capture_mode();
    assert!(matches!(
        read_server_message(control_rx.recv_timeout(Duration::from_millis(100)).unwrap()),
        ServerMessage::MouseCapture {
            enabled: true,
            sgr_pixels: true
        }
    ));
}