Test retained spawn-out animation frames

src/animation.rs

@@ -642,6 +642,27 @@ fn cubic_bezier_point(x1: f32, y1: f32, x2: f32, y2: f32, t: f32) -> CurvePoint
 mod tests {
     use super::*;
 
+    use crate::cmm::cmm_manager::ColorManager;
+
+    fn retained_for_tests() -> Rc<RetainedToplevel> {
+        let color_manager = ColorManager::new();
+        Rc::new(RetainedToplevel {
+            offset: (0, 0),
+            surface: RetainedSurface {
+                offset: (0, 0),
+                size: (100, 100),
+                content: RetainedContent::Color {
+                    color: Color::SOLID_BLACK,
+                    alpha: None,
+                    color_description: color_manager.srgb_gamma22().clone(),
+                    render_intent: RenderIntent::Perceptual,
+                },
+                below: vec![],
+                above: vec![],
+            },
+        })
+    }
+
     #[test]
     fn linear_rect_interpolation_is_symmetric() {
         let a = Rect::new_sized_saturating(0, 0, 100, 100);
@@ -669,6 +690,36 @@ mod tests {
         assert!(AnimationCurve::from_cubic_bezier(0.0, f32::NAN, 0.58, 1.0).is_none());
     }
 
+    #[test]
+    fn spawn_out_frames_shrink_linearly_and_expire() {
+        let state = AnimationState::default();
+        let retained = retained_for_tests();
+        let from = Rect::new_sized_saturating(10, 20, 100, 80);
+        let to = spawn_in_start_rect(from);
+        assert!(state.set_spawn_out(
+            from,
+            2,
+            retained.clone(),
+            true,
+            RetainedExitLayer::Floating,
+            0,
+            160
+        ));
+
+        let start = state.exit_frames(0);
+        assert_eq!(start.len(), 1);
+        assert_eq!(start[0].rect, from);
+        assert_eq!(start[0].source_body_size, (96, 76));
+        assert!(start[0].active);
+        assert_eq!(start[0].layer, RetainedExitLayer::Floating);
+        assert!(Rc::ptr_eq(&start[0].retained, &retained));
+
+        let middle = state.exit_frames(80_000_000);
+        assert_eq!(middle.len(), 1);
+        assert_eq!(middle[0].rect, lerp_rect(from, to, 0.5));
+        assert!(state.exit_frames(160_000_000).is_empty());
+    }
+
     #[test]
     fn unchanged_target_does_not_restart() {
         let state = AnimationState::default();