Selection: Escape tests for a top-level layer, several layers and the focused frame (#2107 review)

One Escape selects nothing for a top-level frame, a top-level layer, two layers in one group,
layers in different parents, and a nested layer with a top-level one. With the focused frame
itself selected, one Escape leaves the focus view.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Model-Effort: Opus 5.5 drove and wrote

crates/engine/src/devfocus_tests.rs

@@ -92,6 +92,12 @@ fn only_the_focused_frame_is_hit_and_escape_leaves() {
     assert_eq!(focused(&s), None, "Escape with nothing selected leaves");
     click(&mut s, 350.0, 100.0);
     assert_eq!(s.selection(), vec![b], "everything is hit again");
+    // With the focused frame itself selected, one Escape leaves the focus view.
+    ex(&mut s, "dev.focus", json!({"id": a}));
+    ex(&mut s, "select.set", json!({"ids": [a]}));
+    assert_eq!(focused(&s), Some(a));
+    s.escape().unwrap();
+    assert_eq!(focused(&s), None, "Escape with the focused frame selected leaves at once");
 }
 
 #[test]

crates/engine/src/selection_behaviour_tests.rs

@@ -277,6 +277,20 @@ fn keyboard_selection() {
     assert_eq!(s.selection(), Vec::<NodeId>::new(), "Esc from a nested layer selects nothing, not the parent");
     s.escape().unwrap();
     assert_eq!(s.selection(), Vec::<NodeId>::new());
+    // A top-level layer, and several layers, nested or not: one Esc selects nothing.
+    let cases: Vec<(Vec<NodeId>, &str)> = vec![
+        (vec![k.f], "a top-level frame"),
+        (vec![k.r], "a top-level layer"),
+        (vec![k.a, k.b], "two layers in one group (not their group)"),
+        (vec![k.a, k.d], "layers in different parents (not the parents)"),
+        (vec![k.a, k.r], "a nested layer and a top-level one"),
+    ];
+    for (ids, why) in cases {
+        ex(&mut s, "select.set", json!({"ids": ids}));
+        assert_eq!(sorted(s.selection()), sorted(ids.clone()), "{why}: selected");
+        s.escape().unwrap();
+        assert_eq!(s.selection(), Vec::<NodeId>::new(), "Esc on {why} selects nothing");
+    }
 }
 
 #[test]