T12b Data Display: DescriptionList, PropertyGrid, Timeline, ActivityFeed, Changelog (review pending: codex 401)

src/data_display/tests.rs

@@ -0,0 +1,65 @@
+use std::{cell::Cell, rc::Rc};
+
+use gpui::{
+    Context, IntoElement, Modifiers, ParentElement, Pixels, Render, Styled, TestAppContext,
+    VisualTestContext, Window, div, point, px,
+};
+
+use super::{PropertyGrid, PropertyGroup};
+use crate::{primitives::Measure, theme::Theme};
+
+/// A property grid whose drawn height the test reads.
+struct Inspector(Rc<Cell<Pixels>>);
+
+impl Render for Inspector {
+    fn render(&mut self, _: &mut Window, _: &mut Context<Self>) -> impl IntoElement {
+        let height = self.0.clone();
+        let editor = || div().h(px(20.0));
+        div().w(px(320.0)).child(
+            Measure::new("measure", move |bounds, _, _| {
+                height.set(bounds.size.height)
+            })
+            .child(
+                PropertyGrid::new("grid")
+                    .group(
+                        PropertyGroup::new("Layout")
+                            .row("Width", editor())
+                            .row("Height", editor()),
+                    )
+                    .group(PropertyGroup::new("Export").folded().row("Scale", editor())),
+            ),
+        )
+    }
+}
+
+/// Frames 2ms apart, past reduced motion's 1ms folds.
+fn settle(cx: &mut VisualTestContext) {
+    for _ in 0..3 {
+        std::thread::sleep(std::time::Duration::from_millis(2));
+        cx.update(|window, _| window.refresh());
+        cx.run_until_parked();
+    }
+}
+
+#[gpui::test]
+fn a_property_group_folds_from_its_header_and_stays_folded(cx: &mut TestAppContext) {
+    cx.update(|cx| {
+        Theme::init(cx);
+        Theme::update(cx, |theme| theme.reduced_motion = true);
+    });
+    let height = Rc::new(Cell::new(Pixels::ZERO));
+    let seen = height.clone();
+    let (_, cx) = cx.add_window_view(|_, _| Inspector(seen));
+    settle(cx);
+    let open = height.get();
+    let header = point(px(4.0), px(12.0));
+    cx.simulate_click(header, Modifiers::none());
+    settle(cx);
+    let folded = height.get();
+    assert!(folded < open, "the rows fold away: {open:?} to {folded:?}");
+    settle(cx);
+    assert_eq!(height.get(), folded, "a new frame keeps the fold");
+    cx.simulate_click(header, Modifiers::none());
+    settle(cx);
+    assert_eq!(height.get(), open, "a second press opens it");
+}