audit combobox

crates/core/tests/field_bench.rs

@@ -38,8 +38,11 @@ impl Render for FieldHost {
     }
 }
 
-/// A field page in a real window, with the url input focused.
-fn field_host() -> (
+/// A field page in a real window; the url input is focused unless
+/// `focus` is false, which leaves the page truly idle.
+fn field_host(
+    focus: bool,
+) -> (
     TestAppContext,
     Entity<InputState>,
     Rc<RefCell<usize>>,
@@ -64,8 +67,10 @@ fn field_host() -> (
     });
     let mut visual = VisualTestContext::from_window(window.into(), &cx);
     visual.update(|window, cx| {
-        let focus = url.read(cx).focus_handle();
-        window.focus(&focus, cx);
+        if focus {
+            let focus = url.read(cx).focus_handle();
+            window.focus(&focus, cx);
+        }
         window.draw(cx).clear(cx);
     });
     (cx, url, renders, visual)
@@ -94,17 +99,27 @@ fn type_and_time(visual: &mut VisualTestContext, text: &str) -> std::time::Durat
 
 #[test]
 fn an_idle_field_page_schedules_no_frames() {
-    let (_cx, _url, _renders, mut visual) = field_host();
+    let (_cx, _url, _renders, mut visual) = field_host(false);
     let frames = visual.update(|window, cx| window.simulate_next_frame(cx));
     assert_eq!(
         frames, 0,
-        "an idle field page must not request animation frames"
+        "an idle unfocused field page must not request animation frames"
+    );
+}
+
+#[test]
+fn a_focused_field_page_schedules_frames_for_its_blink() {
+    let (_cx, _url, _renders, mut visual) = field_host(true);
+    let frames = visual.update(|window, cx| window.simulate_next_frame(cx));
+    assert!(
+        frames > 0,
+        "the focused caret's blink needs frames to redraw at the blink cadence"
     );
 }
 
 #[test]
 fn field_typing_frame_cost() {
-    let (_cx, _url, _renders, mut visual) = field_host();
+    let (_cx, _url, _renders, mut visual) = field_host(true);
     let elapsed = type_and_time(&mut visual, "dsdsadsadadadada");
     assert!(
         elapsed.as_millis() < 1000,