Panics · P09 Overlays: a lightbox or tour past its last item closes

src/overlays/lightbox.rs

@@ -96,15 +96,9 @@ impl Lightbox {
         at: usize,
         on_close: impl Fn(&mut Window, &mut App) + 'static,
     ) -> Self {
-        let slides: Vec<Slide> = slides.into_iter().collect();
-        assert!(
-            slides.is_empty() || at < slides.len(),
-            "slide {at} is past the last of {}",
-            slides.len()
-        );
         Self {
             id: id.into(),
-            slides,
+            slides: slides.into_iter().collect(),
             at,
             on_step: None,
             on_close: Rc::new(on_close),
@@ -140,6 +134,14 @@ impl RenderOnce for Lightbox {
             window.defer(cx, move |window, cx| close(window, cx));
             return div().into_any_element();
         }
+        if at >= count {
+            log::error!(
+                "lightbox {:?}: slide {at} of {count} is gone; closing",
+                self.id
+            );
+            window.defer(cx, move |window, cx| close(window, cx));
+            return div().into_any_element();
+        }
         let step: OnStep = {
             let (id, on_step) = (self.id.clone(), self.on_step);
             Rc::new(move |to, window, cx| {

src/overlays/spotlight.rs

@@ -318,15 +318,9 @@ impl Tour {
         at: usize,
         on_close: impl Fn(&mut Window, &mut App) + 'static,
     ) -> Self {
-        let steps: Vec<TourStep> = steps.into_iter().collect();
-        assert!(
-            at < steps.len(),
-            "step {at} is past the last of {}",
-            steps.len()
-        );
         Self {
             id: id.into(),
-            steps,
+            steps: steps.into_iter().collect(),
             at,
             on_step: None,
             on_close: Rc::new(on_close),
@@ -361,6 +355,11 @@ impl RenderOnce for Tour {
                 }
             })
         };
+        if at >= count {
+            log::error!("tour {:?}: step {at} of {count} is gone; closing", self.id);
+            window.defer(cx, move |window, cx| close(window, cx));
+            return div().into_any_element();
+        }
         let (back, next) = (at.checked_sub(1), (at + 1 < count).then_some(at + 1));
         let current = self.steps[at].clone();
         let turn = motion::changes((self.id.clone(), "at"), at, window, cx);

src/overlays/tests/guides.rs

@@ -352,3 +352,21 @@ fn left_from_back_keeps_the_tour_keys(cx: &mut TestAppContext) {
     press("right", cx);
     assert_eq!(state(&view, cx).1, 1);
 }
+
+#[gpui::test]
+fn a_lightbox_or_tour_past_its_last_closes(cx: &mut TestAppContext) {
+    let (view, cx) = guides(cx);
+    for open in [Open::Lightbox, Open::Tour] {
+        view.update(cx, |guides, cx| {
+            guides.open = Some(open);
+            guides.at = 5;
+            cx.notify();
+        });
+        settle(cx);
+        assert_eq!(
+            view.read_with(cx, |guides, _| guides.open),
+            None,
+            "{open:?}"
+        );
+    }
+}