feat: add status dot component

crates/core/tests/status_dot.rs

@@ -0,0 +1,60 @@
+use gpui::{
+    AppContext as _, IntoElement, ParentElement as _, Render, Styled as _, TestAppContext,
+    VisualTestContext, Window, div,
+};
+use gpui_native_core::status_dot::{StatusDot, StatusDotVariant};
+use gpui_native_theme::{ActiveTheme as _, Theme};
+
+struct DotHost;
+
+impl Render for DotHost {
+    fn render(&mut self, _window: &mut Window, _cx: &mut gpui::Context<Self>) -> impl IntoElement {
+        div().size_full().p_4().child(
+            StatusDot::new("test-dot")
+                .variant(StatusDotVariant::Success)
+                .label("Synced"),
+        )
+    }
+}
+
+fn dot_window() -> (TestAppContext, gpui::AnyWindowHandle) {
+    let mut cx = TestAppContext::single();
+    cx.update(Theme::init);
+    let window = cx.add_window(|_, _| DotHost);
+    let window: gpui::AnyWindowHandle = window.into();
+    cx.update_window(window, |_, window, cx| {
+        window.draw(cx).clear(cx);
+    })
+    .unwrap();
+    (cx, window)
+}
+
+/// A medium dot is half the theme's icon size — big enough to read a state
+/// from, small enough to sit beside row text. The label must not grow it.
+#[test]
+fn the_dot_is_half_the_icon_size() {
+    let (cx, window) = dot_window();
+    let mut visual = VisualTestContext::from_window(window, &cx);
+    let dot = visual.debug_bounds("test-dot").expect("dot missing");
+
+    let side = cx.update(|cx| cx.theme().sizes.medium.icon_size) / 2.;
+    assert!(
+        ((dot.size.width - side).abs() <= gpui::px(0.5))
+            && ((dot.size.height - side).abs() <= gpui::px(0.5)),
+        "the dot must be {side:?} wide, got {:?}",
+        dot.size
+    );
+}
+
+#[test]
+fn the_dot_keeps_a_square_footprint() {
+    let (cx, window) = dot_window();
+    let mut visual = VisualTestContext::from_window(window, &cx);
+    let dot = visual.debug_bounds("test-dot").expect("dot missing");
+
+    assert!(
+        (dot.size.width - dot.size.height).abs() <= gpui::px(0.5),
+        "the dot must stay circular: {:?}",
+        dot.size
+    );
+}