test(tui): add runtime keymap resolver characterization suite

Introduce the TUI runtime keymap resolver and keybinding matching helpers
with a dedicated unit-test suite. This commit is additive only: it adds
resolution logic, conflict validation, parser coverage, and documented macros
without wiring input handlers to the new runtime map yet.

codex-rs/tui/src/key_hint.rs

@@ -15,7 +15,7 @@ const ALT_PREFIX: &str = "alt + ";
 const CTRL_PREFIX: &str = "ctrl + ";
 const SHIFT_PREFIX: &str = "shift + ";
 
-#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
 pub(crate) struct KeyBinding {
     key: KeyCode,
     modifiers: KeyModifiers,
@@ -31,6 +31,22 @@ impl KeyBinding {
             && self.modifiers == event.modifiers
             && (event.kind == KeyEventKind::Press || event.kind == KeyEventKind::Repeat)
     }
+
+    pub(crate) const fn parts(&self) -> (KeyCode, KeyModifiers) {
+        (self.key, self.modifiers)
+    }
+}
+
+/// Matching helpers for one action's keybinding set.
+pub(crate) trait KeyBindingListExt {
+    /// True when any binding in this set matches `event`.
+    fn is_pressed(&self, event: KeyEvent) -> bool;
+}
+
+impl KeyBindingListExt for [KeyBinding] {
+    fn is_pressed(&self, event: KeyEvent) -> bool {
+        self.iter().any(|binding| binding.is_press(event))
+    }
 }
 
 pub(crate) const fn plain(key: KeyCode) -> KeyBinding {
@@ -110,3 +126,60 @@ pub(crate) fn is_altgr(mods: KeyModifiers) -> bool {
 pub(crate) fn is_altgr(_mods: KeyModifiers) -> bool {
     false
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn is_press_accepts_press_and_repeat_but_rejects_release() {
+        let binding = ctrl(KeyCode::Char('k'));
+        let press = KeyEvent::new(KeyCode::Char('k'), KeyModifiers::CONTROL);
+        let repeat = KeyEvent {
+            kind: KeyEventKind::Repeat,
+            ..press
+        };
+        let release = KeyEvent {
+            kind: KeyEventKind::Release,
+            ..press
+        };
+        let wrong_modifiers = KeyEvent::new(KeyCode::Char('k'), KeyModifiers::NONE);
+
+        assert!(binding.is_press(press));
+        assert!(binding.is_press(repeat));
+        assert!(!binding.is_press(release));
+        assert!(!binding.is_press(wrong_modifiers));
+    }
+
+    #[test]
+    fn keybinding_list_ext_matches_any_binding() {
+        let bindings = [plain(KeyCode::Char('a')), ctrl(KeyCode::Char('b'))];
+
+        assert!(bindings.is_pressed(KeyEvent::new(KeyCode::Char('a'), KeyModifiers::NONE)));
+        assert!(bindings.is_pressed(KeyEvent::new(KeyCode::Char('b'), KeyModifiers::CONTROL)));
+        assert!(!bindings.is_pressed(KeyEvent::new(KeyCode::Char('c'), KeyModifiers::NONE)));
+    }
+
+    #[test]
+    fn ctrl_alt_sets_both_modifiers() {
+        assert_eq!(
+            ctrl_alt(KeyCode::Char('v')).parts(),
+            (
+                KeyCode::Char('v'),
+                KeyModifiers::CONTROL | KeyModifiers::ALT
+            )
+        );
+    }
+
+    #[test]
+    fn has_ctrl_or_alt_checks_supported_modifier_combinations() {
+        assert!(!has_ctrl_or_alt(KeyModifiers::NONE));
+        assert!(has_ctrl_or_alt(KeyModifiers::CONTROL));
+        assert!(has_ctrl_or_alt(KeyModifiers::ALT));
+
+        #[cfg(windows)]
+        assert!(!has_ctrl_or_alt(KeyModifiers::CONTROL | KeyModifiers::ALT));
+        #[cfg(not(windows))]
+        assert!(has_ctrl_or_alt(KeyModifiers::CONTROL | KeyModifiers::ALT));
+    }
+}

codex-rs/tui/src/lib.rs

@@ -80,6 +80,7 @@ mod get_git_diff;
 mod history_cell;
 pub mod insert_history;
 mod key_hint;
+mod keymap;
 pub mod live_wrap;
 mod markdown;
 mod markdown_render;