test: the TUI cursor stays drawn beside a side panel and on the tile bar (improvise-gtn7.1)

Both fail on gh/main: the grid at column 4 with any side panel open, the
tile bar at width 42.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VdfEGXA7aJ6ftMsCc9PJze

src/draw.rs

@@ -1120,3 +1120,81 @@ mod title_bar_tests {
         );
     }
 }
+
+#[cfg(test)]
+mod content_tests {
+    use super::{draw, press};
+    use crate::command::key::{KeyCode, KeyEvent, KeyModifiers};
+    use crate::model::cell::{CellKey, CellValue};
+    use crate::ui::app::App;
+    use crate::view::Axis;
+    use crate::workbook::Workbook;
+    use ratatui::{Terminal, backend::TestBackend, style::Color};
+
+    const COLS: usize = 12;
+
+    /// One row, twelve columns, and a value per column that names it.
+    fn wide_grid() -> Workbook {
+        let mut wb = Workbook::new("T");
+        wb.add_category("Row").unwrap();
+        wb.add_category("Col").unwrap();
+        wb.add_item("Row", "R1").unwrap();
+        for i in 0..COLS {
+            let col = format!("Column_{i:02}");
+            wb.add_item("Col", &col).unwrap();
+            let key = CellKey::new(vec![("Row".into(), "R1".into()), ("Col".into(), col)]);
+            wb.model.set_cell(key, CellValue::Number((101 + i) as f64));
+        }
+        wb.active_view_mut().set_axis("Row", Axis::Row);
+        wb.active_view_mut().set_axis("Col", Axis::Column);
+        wb
+    }
+
+    /// The text the whole frame draws in the selected cell's style.
+    fn selected_text(app: &App) -> String {
+        let (w, h) = (app.term_width, app.term_height);
+        let mut terminal = Terminal::new(TestBackend::new(w, h)).expect("test backend");
+        terminal.draw(|f| draw(f, app)).expect("draw");
+        terminal
+            .backend()
+            .buffer()
+            .content()
+            .iter()
+            .filter(|c| c.bg == Color::Cyan && c.fg == Color::Black)
+            .map(|c| c.symbol())
+            .collect()
+    }
+
+    /// improvise-gtn7.1: the cursor went behind a side panel —
+    /// `context/test-evidence/tui.md`.
+    #[test]
+    fn moving_right_keeps_the_selected_cell_drawn_beside_any_side_panel() {
+        let panels: [(&str, fn(&mut App)); 4] = [
+            ("no", |_| {}),
+            ("formula", |a| a.view_state.formula_panel_open = true),
+            ("category", |a| a.view_state.category_panel_open = true),
+            ("view", |a| a.view_state.view_panel_open = true),
+        ];
+        for (panel, open) in panels {
+            let mut app = App::new(wide_grid(), None);
+            (app.term_width, app.term_height) = (80, 24);
+            // The category panel is open at launch; close all three first.
+            let vs = &mut app.view_state;
+            (vs.formula_panel_open, vs.category_panel_open, vs.view_panel_open) =
+                (false, false, false);
+            open(&mut app);
+            for step in 1..COLS {
+                press(&mut app, KeyEvent::new(KeyCode::Right, KeyModifiers::NONE)).unwrap();
+                let col = app.cursor().selected.1;
+                assert_eq!(col, step, "setup: {panel} panel, the cursor moved");
+                let drawn = selected_text(&app);
+                assert!(
+                    drawn.contains(&(101 + col).to_string()),
+                    "{panel} panel: column {col} is selected (offset {}) but not \
+                     drawn; the selection drew {drawn:?}",
+                    app.cursor().col_offset
+                );
+            }
+        }
+    }
+}

src/ui/tile_bar.rs

@@ -231,6 +231,38 @@ mod tests {
         }
     }
 
+    /// improvise-gtn7.1: the tile cursor could scroll off the bar —
+    /// `context/test-evidence/tui.md`.
+    #[test]
+    fn the_selected_tile_is_drawn_at_every_width_it_fits_in() {
+        let mut wb = Workbook::new("Test");
+        for i in 0..8 {
+            wb.add_category(&format!("Category_{i}")).unwrap();
+        }
+        let app = App::new(wb, None);
+        let cache = project::tile_bar_of(&app);
+        let names: Vec<&str> = cache.tiles.iter().map(|t| t.category.as_str()).collect();
+        assert!(names.len() > 8, "setup: more tiles than any tested width holds");
+        for width in 40u16..=200 {
+            for (sel, name) in names.iter().enumerate() {
+                let area = Rect::new(0, 0, width, 1);
+                let mut buf = Buffer::empty(area);
+                TileBar::new(&cache, &AppMode::TileSelect, sel).render(area, &mut buf);
+                let highlighted: String = buf
+                    .content()
+                    .iter()
+                    .filter(|c| c.bg == Color::Cyan)
+                    .map(|c| c.symbol())
+                    .collect();
+                assert!(
+                    highlighted.contains(&format!("[{name} ")),
+                    "width {width}: tile {sel} ({name}) is selected but not drawn: {:?}",
+                    buf_text(&buf)
+                );
+            }
+        }
+    }
+
     /// The tiles themselves are what the bar is for, and deleting the hint must
     /// not delete them. improvise-rr8n.
     #[test]