test(keyboard): shortcuts, pin the key-up action list on both sides

kShortcutActionsRunOnKeyUp and runs_on_release are two hand-kept lists of
the actions that run on key release. Add a shared fixture and check each
side against it, the way the key vocabulary and the default bindings are
already checked, so adding a focus-changing action on one side breaks a
test until the other side follows. The Dart test also checks that every
listed id is a configurable action.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Ra4my61t8q1FN5n59wB16D

flutter/lib/common/widgets/keyboard_shortcuts/shortcut_constants.dart

@@ -23,7 +23,8 @@ const kShortcutActionSwitchTabPrev = 'switch_tab_prev';
 /// that consumed the press also sees its repeats and its release. On Linux a
 /// legacy-mode session matches in Dart while a map-mode session matches in
 /// Rust, and neither knows the other's fired keys. Mirrors `runs_on_release`
-/// in `src/keyboard/shortcuts.rs`.
+/// in `src/keyboard/shortcuts.rs`; both are checked against
+/// `flutter/test/fixtures/key_up_shortcut_actions.json`.
 const kShortcutActionsRunOnKeyUp = {
   kShortcutActionCloseTab,
   kShortcutActionSwitchTabNext,

flutter/test/fixtures/key_up_shortcut_actions.json

@@ -0,0 +1,5 @@
+[
+  "close_tab",
+  "switch_tab_next",
+  "switch_tab_prev"
+]

flutter/test/keyboard_shortcuts_test.dart

@@ -509,6 +509,25 @@ void main() {
     expect(shortcutKeyNameForEvent(qwertzZ), 'y');
   });
 
+  test('kShortcutActionsRunOnKeyUp matches the fixture and names real actions',
+      () {
+    // Rust has a mirror test against the same file
+    // (`key_up_actions_match_fixture` in src/keyboard/shortcuts.rs).
+    final fixture = (jsonDecode(
+                File('test/fixtures/key_up_shortcut_actions.json')
+                    .readAsStringSync()) as List<dynamic>)
+        .cast<String>()
+        .toSet();
+    expect(kShortcutActionsRunOnKeyUp, equals(fixture),
+        reason: 'kShortcutActionsRunOnKeyUp drifted from the fixture — update '
+            'shortcut_constants.dart, the fixture, and Rust runs_on_release '
+            'together');
+    final actions = idSet(kKeyboardShortcutActionGroups);
+    for (final id in kShortcutActionsRunOnKeyUp) {
+      expect(actions, contains(id), reason: '"$id" is not a configurable action');
+    }
+  });
+
   test('configurable shortcut list does not include known-removed action IDs',
       () {
     // These IDs were briefly defined without handlers (a "ghost action"

src/keyboard/shortcuts.rs

@@ -343,12 +343,16 @@ lazy_static::lazy_static! {
 /// that consumed the press also sees its repeats and its release. The next
 /// session may route its keys through the other matcher (Flutter's legacy
 /// path on Linux), which never saw the press. Mirrors
-/// `kShortcutActionsRunOnKeyUp` in `shortcut_constants.dart`.
+/// `kShortcutActionsRunOnKeyUp` in `shortcut_constants.dart`; both are
+/// checked against `flutter/test/fixtures/key_up_shortcut_actions.json`.
+const RELEASE_ACTION_IDS: &[&str] = &[
+    action_id::CLOSE_TAB,
+    action_id::SWITCH_TAB_NEXT,
+    action_id::SWITCH_TAB_PREV,
+];
+
 pub fn runs_on_release(action_id: &str) -> bool {
-    matches!(
-        action_id,
-        action_id::CLOSE_TAB | action_id::SWITCH_TAB_NEXT | action_id::SWITCH_TAB_PREV
-    )
+    RELEASE_ACTION_IDS.contains(&action_id)
 }
 
 /// Forget the modifiers a session released on its remote and the actions it
@@ -1237,6 +1241,29 @@ mod tests {
         release_chord(chord);
     }
 
+    /// The Dart matcher keeps the same list (`kShortcutActionsRunOnKeyUp`);
+    /// the fixture is the shared source of truth.
+    #[test]
+    fn key_up_actions_match_fixture() {
+        use std::collections::BTreeSet;
+
+        let fixture: Vec<String> = serde_json::from_str(include_str!(
+            "../../flutter/test/fixtures/key_up_shortcut_actions.json"
+        ))
+        .expect("parse fixture");
+        let expected: BTreeSet<&str> = fixture.iter().map(String::as_str).collect();
+        let actual: BTreeSet<&str> = RELEASE_ACTION_IDS.iter().copied().collect();
+        assert_eq!(
+            actual, expected,
+            "runs_on_release drifted from key_up_shortcut_actions.json — update \
+             shortcuts.rs, the fixture, and Dart kShortcutActionsRunOnKeyUp together"
+        );
+        for id in &fixture {
+            assert!(runs_on_release(id));
+        }
+        assert!(!runs_on_release(action_id::SCREENSHOT));
+    }
+
     /// Close tab and tab switching move focus away before the key is
     /// released; they run on the release so the same matcher sees the whole
     /// press.