Add support structures and stress mechanics

Introduce support structures (roof supports) and a stress system that
propagates from bases through tunnels, causing collapses when stress
reaches 100 %.  Add auto‑support feature with toggleable tasks, new
keybindings (Tasks, AutoSupports, Stress), and a support‑building tab.
Implement collapsed tunnels, support work progress, and related UI
rendering (stress view, auto‑support indicators).  Extend board resize
logic, update game state structs, and adjust keybinding actions.  Update
documentation (README, AGENTS, CODE_MAP, PROGRESS, TESTING) to reflect
new features.  Add flake.nix dependencies (bash, gitea‑actions‑runner,
docker).  Add extensive tests for tunnel stress, support building,
auto‑supports, and related mechanics.

tests/tunnel_stress.rs

@@ -0,0 +1,610 @@
+use clap::Parser;
+use ratatui::{
+    Terminal,
+    backend::TestBackend,
+    buffer::{Buffer, Cell},
+    crossterm::event::{KeyCode, KeyEvent, KeyModifiers},
+    layout::Rect,
+    style::Color,
+    widgets::Widget,
+};
+use std::sync::mpsc::{Receiver, Sender, channel};
+use war_in_tunnels::{
+    app::{
+        Action, App, GameStates, View, available_skirmish_actions, handle_keybindings,
+        states::{
+            SkirmishState,
+            skirmish_states::{
+                BoardState, CellSizes, Players, Resources, ZoomLevel,
+                structures::{CollapsedTunnel, Structure, Structures, Tunnel},
+                tasks::{DiggingTask, MovingTask, Task, Tasks},
+                units::{MinerUnit, Unit, Units},
+            },
+        },
+        threads::AudioCmd,
+    },
+    cli::Cli,
+};
+
+fn app() -> App {
+    let args: Cli = Cli::try_parse_from(["game", "--disable-audio"]).unwrap();
+    let (tx, _rx): (Sender<AudioCmd>, Receiver<AudioCmd>) = channel();
+    let mut app: App = App::new(args, tx);
+    app.view = View::Skirmish;
+    app.window_area = Rect::new(0, 0, 160, 50);
+    app.states = Some(GameStates::new(&app.args, &app.window_area));
+    app
+}
+
+fn put_tunnel(board: &mut BoardState, coords: (usize, usize), supported: bool) -> () {
+    let mut tunnel: Tunnel = Tunnel::new();
+    tunnel.set_support(supported);
+    board.cells[coords.0][coords.1].set_structure(Structures::Tunnel(tunnel));
+}
+
+fn miner(board: &mut BoardState, coords: (usize, usize), owner: Players) -> () {
+    *board.cells[coords.0][coords.1].get_mut_option_unit() =
+        Some(Units::Miner(MinerUnit::new(owner, coords)));
+}
+
+fn press(app: &mut App, code: KeyCode) -> () {
+    handle_keybindings(app, KeyEvent::new(code, KeyModifiers::NONE));
+}
+
+fn finish_support_work(game: &mut SkirmishState) -> () {
+    for _ in 0..Tunnel::SUPPORT_WORK_TICKS {
+        game.advance_support_work();
+    }
+}
+
+#[test]
+fn support_work_takes_three_seconds_freezes_worker_and_pauses_without_builder() -> () {
+    let mut app: App = app();
+    let game: &mut SkirmishState = &mut app.states_mut().unwrap().skirmish;
+    put_tunnel(&mut game.board, (5, 3), false);
+    game.board.cells[5][2]
+        .get_mut_option_unit()
+        .set_task(Tasks::Moving(MovingTask::new([(5, 3)].into())));
+    assert!(game.build_support((5, 3), Players::Player));
+    for _ in 1..Tunnel::SUPPORT_WORK_TICKS {
+        game.tick_update();
+    }
+    assert_eq!(game.board.cells[5][3].get_structure().get_level(), ' ');
+    assert_eq!(
+        game.board.cells[5][2].get_ref_option_unit().get_ref_tasks()[0].get_progress(),
+        0.0
+    );
+    game.tick_update();
+    assert_eq!(game.board.cells[5][3].get_structure().get_level(), 'T');
+    assert!(game.board.cells[5][2].get_ref_option_unit().get_ref_tasks()[0].get_progress() > 0.0);
+    assert!(game.remove_support((5, 3), Players::Player));
+    for _ in 0..45 {
+        game.tick_update();
+    }
+    game.board.cells[5][2].get_mut_option_unit().take();
+    let paused: Structures = game.board.cells[5][3].get_structure();
+    for _ in 0..20 {
+        game.tick_update();
+    }
+    assert_eq!(game.board.cells[5][3].get_structure(), paused);
+    assert_eq!(paused.get_level(), 'T');
+    miner(&mut game.board, (5, 2), Players::Player);
+    for _ in 45..Tunnel::SUPPORT_WORK_TICKS {
+        game.tick_update();
+    }
+    assert_eq!(game.board.cells[5][3].get_structure().get_level(), ' ');
+}
+
+#[test]
+fn one_miner_cannot_work_on_two_supports_simultaneously() -> () {
+    let mut app: App = app();
+    let game: &mut SkirmishState = &mut app.states_mut().unwrap().skirmish;
+    put_tunnel(&mut game.board, (5, 3), false);
+    put_tunnel(&mut game.board, (5, 4), false);
+    miner(&mut game.board, (5, 3), Players::Player);
+    assert!(game.build_support((5, 3), Players::Player));
+    assert!(game.build_support((5, 4), Players::Player));
+    finish_support_work(game);
+    assert_eq!(game.board.cells[5][3].get_structure().get_level(), 'T');
+    let Structures::Tunnel(tunnel) = game.board.cells[5][4].get_structure() else {
+        panic!("tunnel missing");
+    };
+    assert_eq!(tunnel.support_progress(), Some(0));
+    finish_support_work(game);
+    assert_eq!(game.board.cells[5][4].get_structure().get_level(), 'T');
+}
+
+#[test]
+fn stress_map_renders_stone_normally_at_every_zoom() -> () {
+    let app: App = app();
+    for zoom in [
+        ZoomLevel::Default,
+        ZoomLevel::ZoomedIn,
+        ZoomLevel::ZoomedOut,
+    ] {
+        for (selected, marked) in [(false, false), (false, true), (true, false), (true, true)] {
+            let area: Rect = Rect::new(
+                0,
+                0,
+                zoom.get_cell_size(CellSizes::Width) as u16,
+                zoom.get_cell_size(CellSizes::Height) as u16,
+            );
+            let mut normal: Buffer = Buffer::empty(area);
+            let mut stress: Buffer = Buffer::empty(area);
+            app.states_ref().unwrap().skirmish.board.cells[5][4]
+                .clone()
+                .set_zoom_level(zoom)
+                .set_selected(selected)
+                .set_marked(selected && marked)
+                .clone()
+                .render(area, &mut normal);
+            app.states_ref().unwrap().skirmish.board.cells[5][4]
+                .clone()
+                .set_zoom_level(zoom)
+                .set_selected(selected)
+                .set_marked(marked)
+                .render_stress(area, &mut stress);
+            assert_eq!(normal, stress);
+            assert!(
+                !stress
+                    .content
+                    .iter()
+                    .any(|cell: &Cell| -> bool { cell.symbol() == "%" })
+            );
+        }
+    }
+}
+
+#[test]
+fn task_key_requires_space_selection_and_moving_choice_resets_invalid_draft() -> () {
+    let mut app: App = app();
+    press(&mut app, KeyCode::Left);
+    assert!(
+        !available_skirmish_actions(&app.states_ref().unwrap().skirmish).contains(&Action::Tasks)
+    );
+    press(&mut app, KeyCode::Char('t'));
+    assert!(!app.states_ref().unwrap().skirmish.task_view);
+    press(&mut app, KeyCode::Char(' '));
+    assert!(
+        available_skirmish_actions(&app.states_ref().unwrap().skirmish).contains(&Action::Tasks)
+    );
+    press(&mut app, KeyCode::Right);
+    press(&mut app, KeyCode::Char('t'));
+    assert!(app.states_ref().unwrap().skirmish.task_view);
+    press(&mut app, KeyCode::Right);
+    press(&mut app, KeyCode::Enter);
+    let board: &BoardState = &app.states_ref().unwrap().skirmish.board;
+    assert!(board.marked_cells.marking_cells && board.movement_only);
+    assert_eq!(board.get_focused_cell().get_coords(), (5, 2));
+    assert_eq!(board.get_marked_cells().len(), 1);
+    assert!(
+        board.cells[5][2]
+            .get_ref_option_unit()
+            .get_ref_tasks()
+            .is_empty()
+    );
+    press(&mut app, KeyCode::Esc);
+    assert!(
+        !available_skirmish_actions(&app.states_ref().unwrap().skirmish).contains(&Action::Tasks)
+    );
+}
+
+#[test]
+fn stress_follows_cardinal_distance_from_base_and_caps_at_100() -> () {
+    let mut app: App = app();
+    let board: &mut BoardState = &mut app.states_mut().unwrap().skirmish.board;
+    for col in 3..=9 {
+        put_tunnel(board, (5, col), false);
+    }
+    put_tunnel(board, (4, 3), false);
+    put_tunnel(board, (6, 3), false);
+    board.recalculate_stress();
+    for (col, stress) in [(3, 20), (4, 40), (5, 60), (6, 80), (7, 100), (9, 100)] {
+        assert_eq!(board.cells[5][col].get_structure().get_stress(), stress);
+    }
+    assert_eq!(board.cells[4][3].get_structure().get_stress(), 40);
+    assert_eq!(board.cells[6][3].get_structure().get_stress(), 40);
+}
+
+#[test]
+fn support_stabilizes_all_four_directions_and_has_level_marker() -> () {
+    let mut app: App = app();
+    let board: &mut BoardState = &mut app.states_mut().unwrap().skirmish.board;
+    put_tunnel(board, (5, 12), true);
+    for coords in [(4, 12), (6, 12), (5, 11), (5, 13)] {
+        put_tunnel(board, coords, false);
+    }
+    board.recalculate_stress();
+    assert_eq!(board.cells[5][12].get_structure().get_level(), 'T');
+    assert_eq!(board.cells[5][12].get_structure().get_stress(), 20);
+    for (row, col) in [(4, 12), (6, 12), (5, 11), (5, 13)] {
+        assert_eq!(board.cells[row][col].get_structure().get_stress(), 40);
+    }
+    assert_eq!(board.resolve_collapses(), 0);
+}
+
+#[test]
+fn removal_causes_fatal_cascade_and_preserves_safe_tunnels() -> () {
+    let mut app: App = app();
+    let game: &mut SkirmishState = &mut app.states_mut().unwrap().skirmish;
+    for col in 3..=9 {
+        put_tunnel(&mut game.board, (5, col), col == 6);
+    }
+    miner(&mut game.board, (5, 6), Players::Player);
+    miner(&mut game.board, (5, 8), Players::Player);
+    miner(&mut game.board, (5, 9), Players::Enemy);
+    game.board.resolve_collapses();
+    assert!(game.remove_support((5, 6), Players::Player));
+    for _ in 1..Tunnel::SUPPORT_WORK_TICKS {
+        game.advance_support_work();
+    }
+    assert_eq!(game.board.cells[5][6].get_structure().get_level(), 'T');
+    assert!(game.board.cells[5][9].get_ref_option_unit().is_some());
+    game.advance_support_work();
+    for col in 7..=9 {
+        let structure: Structures = game.board.cells[5][col].get_structure();
+        assert!(matches!(structure, Structures::CollapsedTunnel(_)));
+        assert_eq!(structure.get_durability(), 750);
+        assert!(game.board.cells[5][col].get_ref_option_unit().is_none());
+        assert!(
+            !structure.can_enter(
+                game.board.cells[5][6]
+                    .get_ref_option_unit()
+                    .as_ref()
+                    .unwrap()
+            )
+        );
+    }
+    assert!(game.board.cells[5][6].get_ref_option_unit().is_some());
+    assert_eq!(game.board.cells[5][6].get_structure().get_stress(), 80);
+    assert_eq!(game.board.resolve_collapses(), 0);
+}
+
+#[test]
+fn alternate_support_prevents_collapse_after_removal() -> () {
+    let mut app: App = app();
+    let game: &mut SkirmishState = &mut app.states_mut().unwrap().skirmish;
+    for col in 3..=10 {
+        put_tunnel(&mut game.board, (5, col), col == 6 || col == 9);
+    }
+    miner(&mut game.board, (5, 6), Players::Player);
+    assert!(game.remove_support((5, 6), Players::Player));
+    finish_support_work(game);
+    assert!(matches!(
+        game.board.cells[5][8].get_structure(),
+        Structures::Tunnel(_)
+    ));
+    assert_eq!(game.board.cells[5][8].get_structure().get_stress(), 40);
+}
+
+#[test]
+fn supports_charge_atomically_require_local_builder_and_do_not_refund_removal() -> () {
+    let mut app: App = app();
+    let game: &mut SkirmishState = &mut app.states_mut().unwrap().skirmish;
+    put_tunnel(&mut game.board, (5, 3), false);
+    put_tunnel(&mut game.board, (5, 15), false);
+    let before: Resources = game.player_resources;
+    assert!(!game.build_support((usize::MAX, 0), Players::Player));
+    assert!(!game.build_support((5, 15), Players::Player));
+    assert!(!game.build_support((5, 3), Players::Enemy));
+    assert_eq!(game.player_resources, before);
+    game.player_resources = Resources::new(9, 100);
+    assert!(!game.build_support((5, 3), Players::Player));
+    assert_eq!(game.player_resources, Resources::new(9, 100));
+    game.player_resources = Resources::new(10, 2);
+    assert!(game.build_support((5, 3), Players::Player));
+    assert_eq!(game.player_resources, Resources::new(0, 0));
+    assert!(!game.build_support((5, 3), Players::Player));
+    assert!(!game.remove_support((5, 3), Players::Player));
+    finish_support_work(game);
+    assert!(game.remove_support((5, 3), Players::Player));
+    assert_eq!(game.player_resources, Resources::new(0, 0));
+    assert!(!game.remove_support((5, 3), Players::Player));
+}
+
+#[test]
+fn support_building_tab_builds_and_removes_upgrade_using_local_miner() -> () {
+    let mut app: App = app();
+    put_tunnel(&mut app.states_mut().unwrap().skirmish.board, (5, 3), false);
+    press(&mut app, KeyCode::Char('b'));
+    press(&mut app, KeyCode::Right);
+    assert_eq!(app.states_ref().unwrap().skirmish.selected_building, 1);
+    press(&mut app, KeyCode::Enter);
+    let game: &SkirmishState = &app.states_ref().unwrap().skirmish;
+    assert_eq!(game.board.cells[5][3].get_structure().get_level(), ' ');
+    finish_support_work(&mut app.states_mut().unwrap().skirmish);
+    let game: &SkirmishState = &app.states_ref().unwrap().skirmish;
+    assert_eq!(game.board.cells[5][3].get_structure().get_level(), 'T');
+    assert_eq!(game.player_resources, Resources::new(40, 23));
+    press(&mut app, KeyCode::Delete);
+    assert_eq!(
+        app.states_ref().unwrap().skirmish.board.cells[5][3]
+            .get_structure()
+            .get_level(),
+        'T'
+    );
+    finish_support_work(&mut app.states_mut().unwrap().skirmish);
+    assert_eq!(
+        app.states_ref().unwrap().skirmish.board.cells[5][3]
+            .get_structure()
+            .get_level(),
+        ' '
+    );
+    assert_eq!(
+        app.states_ref().unwrap().skirmish.player_resources,
+        Resources::new(40, 23)
+    );
+    assert!(app.states_ref().unwrap().skirmish.building_view);
+}
+
+#[test]
+fn rubble_requires_less_work_than_stone_and_percent_is_rendered() -> () {
+    let mut app: App = app();
+    let game: &mut SkirmishState = &mut app.states_mut().unwrap().skirmish;
+    game.board.cells[5][3].set_structure(Structures::CollapsedTunnel(CollapsedTunnel::new()));
+    game.board.cells[5][2]
+        .get_mut_option_unit()
+        .set_task(Tasks::Digging(DiggingTask::new([(5, 3)].into(), 25.0)));
+    game.tick_update();
+    assert_eq!(game.board.cells[5][3].get_structure().get_durability(), 500);
+    let area: Rect = Rect::new(0, 0, 9, 5);
+    let mut buffer: Buffer = Buffer::empty(area);
+    game.board.cells[5][3].clone().render(area, &mut buffer);
+    let text: String = buffer
+        .content
+        .iter()
+        .map(|cell: &Cell| -> &str { cell.symbol() })
+        .collect();
+    assert!(text.contains("66%"));
+    for _ in 0..2 {
+        game.tick_update();
+    }
+    assert!(game.board.cells[5][3].get_ref_option_unit().is_some());
+    assert!(matches!(
+        game.board.cells[5][3].get_structure(),
+        Structures::Tunnel(_)
+    ));
+}
+
+#[test]
+fn automatic_supports_are_spaced_at_last_safe_tiles_and_do_not_waste_final_support() -> () {
+    let mut app: App = app();
+    let game: &mut SkirmishState = &mut app.states_mut().unwrap().skirmish;
+    game.player_resources = Resources::new(1000, 1000);
+    game.board.cells[5][2]
+        .get_mut_option_unit()
+        .set_task(Tasks::Digging(DiggingTask::new(
+            (3..=12)
+                .map(|col: usize| -> (usize, usize) { (5, col) })
+                .collect(),
+            100.0,
+        )));
+    for _ in 0..400 {
+        game.tick_update();
+        if game.board.cells[5][12].get_ref_option_unit().is_some() {
+            break;
+        }
+    }
+    assert!(game.board.cells[5][12].get_ref_option_unit().is_some());
+    assert_eq!(game.player_resources, Resources::new(985, 996));
+    assert!(game.turn_counter >= u64::from(2 * Tunnel::SUPPORT_WORK_TICKS));
+    for col in 3..=12 {
+        let Structures::Tunnel(tunnel) = game.board.cells[5][col].get_structure() else {
+            panic!("collapsed at {col}");
+        };
+        assert_eq!(tunnel.has_support(), col == 6 || col == 9);
+        assert!(tunnel.get_stress() < 100);
+    }
+}
+
+#[test]
+fn disabled_auto_supports_or_missing_funds_kills_miner_at_fifth_tile() -> () {
+    for (automatic, metal) in [(false, 100), (true, 0)] {
+        let mut app: App = app();
+        let game: &mut SkirmishState = &mut app.states_mut().unwrap().skirmish;
+        game.player_resources = Resources::new(100, metal);
+        let mut task: DiggingTask = DiggingTask::new(
+            (3..=9)
+                .map(|col: usize| -> (usize, usize) { (5, col) })
+                .collect(),
+            100.0,
+        );
+        task.set_auto_supports(automatic);
+        game.board.cells[5][2]
+            .get_mut_option_unit()
+            .set_task(Tasks::Digging(task));
+        for _ in 0..5 {
+            game.tick_update();
+        }
+        assert!(matches!(
+            game.board.cells[5][7].get_structure(),
+            Structures::CollapsedTunnel(_)
+        ));
+        assert!(game.board.cells[5][7].get_ref_option_unit().is_none());
+        assert_eq!(game.player_resources, Resources::new(100, metal));
+    }
+}
+
+#[test]
+fn rubble_can_be_dug_again_and_auto_setting_survives_task_conversion() -> () {
+    let mut app: App = app();
+    let game: &mut SkirmishState = &mut app.states_mut().unwrap().skirmish;
+    game.board.cells[5][3].set_structure(Structures::CollapsedTunnel(CollapsedTunnel::new()));
+    let mut task: MovingTask = MovingTask::new([(5, 3)].into());
+    task.set_auto_supports(false);
+    let dig: DiggingTask = DiggingTask::from_moving(task, 100.0);
+    assert!(!dig.auto_supports());
+    assert!(!MovingTask::from_digging(dig.clone()).auto_supports());
+    game.board.cells[5][2]
+        .get_mut_option_unit()
+        .set_task(Tasks::Digging(dig));
+    game.tick_update();
+    assert!(matches!(
+        game.board.cells[5][3].get_structure(),
+        Structures::Tunnel(_)
+    ));
+    assert!(game.board.cells[5][3].get_ref_option_unit().is_some());
+}
+
+#[test]
+fn stress_view_hides_all_other_text_and_colors_but_keeps_focused_color() -> () {
+    let mut app: App = app();
+    let game: &mut SkirmishState = &mut app.states_mut().unwrap().skirmish;
+    put_tunnel(&mut game.board, (5, 3), true);
+    miner(&mut game.board, (5, 3), Players::Player);
+    game.board.recalculate_stress();
+    for zoom in [
+        ZoomLevel::Default,
+        ZoomLevel::ZoomedIn,
+        ZoomLevel::ZoomedOut,
+    ] {
+        let area: Rect = Rect::new(
+            0,
+            0,
+            zoom.get_cell_size(CellSizes::Width) as u16,
+            zoom.get_cell_size(CellSizes::Height) as u16,
+        );
+        let mut buffer: Buffer = Buffer::empty(area);
+        game.board.cells[5][3]
+            .clone()
+            .set_zoom_level(zoom)
+            .set_selected(false)
+            .set_marked(true)
+            .render_stress(area, &mut buffer);
+        let text: String = buffer
+            .content
+            .iter()
+            .map(|cell: &Cell| -> &str { cell.symbol() })
+            .collect();
+        assert!(text.contains("20%"));
+        assert!(!text.contains('M') && !text.contains('T'));
+        assert!(!buffer.content.iter().any(|cell: &Cell| -> bool {
+            matches!(cell.fg, Color::Magenta | Color::LightMagenta | Color::Blue)
+        }));
+        game.board.cells[5][3]
+            .clone()
+            .set_selected(true)
+            .render_stress(area, &mut buffer);
+        assert_eq!(buffer[(0, 0)].fg, Color::LightYellow);
+        game.board.cells[5][3]
+            .clone()
+            .set_selected(true)
+            .set_marked(true)
+            .render_stress(area, &mut buffer);
+        assert_eq!(buffer[(0, 0)].fg, Color::Magenta);
+    }
+}
+
+#[test]
+fn task_sidebar_selects_auto_supports_and_captures_setting_in_queued_task() -> () {
+    let mut app: App = app();
+    press(&mut app, KeyCode::Left);
+    press(&mut app, KeyCode::Char(' '));
+    let coords: (usize, usize) = app
+        .states_ref()
+        .unwrap()
+        .skirmish
+        .board
+        .get_focused_cell()
+        .get_coords();
+    press(&mut app, KeyCode::Char('t'));
+    assert!(app.states_ref().unwrap().skirmish.task_view);
+    press(&mut app, KeyCode::Char('a'));
+    press(&mut app, KeyCode::Char('s'));
+    assert!(app.states_ref().unwrap().skirmish.stress_view);
+    assert!(!app.states_ref().unwrap().skirmish.board.auto_supports);
+    assert_eq!(
+        app.states_ref()
+            .unwrap()
+            .skirmish
+            .board
+            .get_focused_cell()
+            .get_coords(),
+        coords
+    );
+    let mut terminal: Terminal<TestBackend> = Terminal::new(TestBackend::new(160, 50)).unwrap();
+    terminal
+        .draw(|frame: &mut ratatui::Frame<'_>| -> () {
+            frame.render_widget(&mut app, frame.area());
+        })
+        .unwrap();
+    let text: String = terminal
+        .backend()
+        .buffer()
+        .content
+        .iter()
+        .map(|cell: &Cell| -> &str { cell.symbol() })
+        .collect();
+    assert!(text.contains("Auto supports: OFF"));
+    assert!(text.contains("Unit tasks"));
+    let title: usize = terminal
+        .backend()
+        .buffer()
+        .content
+        .windows("Unit tasks".len())
+        .position(|cells: &[Cell]| -> bool {
+            cells
+                .iter()
+                .map(|cell: &Cell| -> &str { cell.symbol() })
+                .collect::<String>()
+                == "Unit tasks"
+        })
+        .unwrap();
+    assert!(title % 160 > 100);
+    press(&mut app, KeyCode::Esc);
+    assert!(app.states_ref().unwrap().skirmish.task_view);
+    press(&mut app, KeyCode::Enter);
+    assert!(!app.states_ref().unwrap().skirmish.task_view);
+    assert!(
+        app.states_ref()
+            .unwrap()
+            .skirmish
+            .board
+            .marked_cells
+            .marking_cells
+    );
+    press(&mut app, KeyCode::Right);
+    press(&mut app, KeyCode::Char(' '));
+    assert!(
+        !app.states_ref().unwrap().skirmish.board.cells[5][2]
+            .get_ref_option_unit()
+            .get_ref_tasks()[0]
+            .auto_supports()
+    );
+}
+
+#[test]
+fn moving_choice_rejects_stone_and_never_digs_collapsed_route() -> () {
+    let mut app: App = app();
+    put_tunnel(&mut app.states_mut().unwrap().skirmish.board, (5, 3), false);
+    press(&mut app, KeyCode::Left);
+    press(&mut app, KeyCode::Char(' '));
+    press(&mut app, KeyCode::Char('t'));
+    press(&mut app, KeyCode::Right);
+    assert_eq!(app.states_ref().unwrap().skirmish.selected_task, 1);
+    press(&mut app, KeyCode::Enter);
+    press(&mut app, KeyCode::Right);
+    press(&mut app, KeyCode::Right);
+    assert_eq!(
+        app.states_ref()
+            .unwrap()
+            .skirmish
+            .board
+            .get_focused_cell()
+            .get_coords(),
+        (5, 3)
+    );
+    press(&mut app, KeyCode::Char(' '));
+    let game: &mut SkirmishState = &mut app.states_mut().unwrap().skirmish;
+    let Tasks::Moving(task) = &game.board.cells[5][2].get_ref_option_unit().get_ref_tasks()[0]
+    else {
+        panic!("not moving");
+    };
+    assert!(!task.dig_if_blocked);
+    game.board.cells[5][3].set_structure(Structures::CollapsedTunnel(CollapsedTunnel::new()));
+    for _ in 0..200 {
+        game.tick_update();
+    }
+    assert_eq!(game.board.cells[5][3].get_structure().get_durability(), 750);
+    assert!(game.board.cells[5][2].get_ref_option_unit().is_some());
+}