new rendering engine

crates/client-domain/tests/scroll_tests.rs

@@ -0,0 +1,72 @@
+use client_domain::ScrollState;
+use std::time::Duration;
+
+#[test]
+fn no_overflow_means_zero_offset() {
+    let scroll = ScrollState::new(100, 80);
+    assert_eq!(scroll.offset(), 0);
+    assert!(!scroll.is_active());
+}
+
+#[test]
+fn overflow_starts_at_zero_offset() {
+    let scroll = ScrollState::new(100, 200);
+    assert_eq!(scroll.offset(), 0);
+    assert!(scroll.is_active());
+}
+
+#[test]
+fn tick_advances_offset_after_initial_pause() {
+    let mut scroll = ScrollState::new(100, 200);
+    // Overflow = 100px. Initial pause = 2s.
+    // Tick past the pause
+    assert!(scroll.tick(Duration::from_secs(3)));
+    assert!(scroll.offset() > 0);
+}
+
+#[test]
+fn tick_returns_false_when_no_movement() {
+    let mut scroll = ScrollState::new(100, 80);
+    assert!(!scroll.tick(Duration::from_millis(100)));
+}
+
+#[test]
+fn offset_never_exceeds_overflow() {
+    let mut scroll = ScrollState::new(100, 200);
+    // Tick many times — offset should cap at overflow (100)
+    for _ in 0..1000 {
+        scroll.tick(Duration::from_millis(100));
+    }
+    assert!(scroll.offset() <= 100);
+}
+
+#[test]
+fn bounces_back_after_reaching_end() {
+    let mut scroll = ScrollState::new(100, 150);
+    // Overflow = 50px. Tick until we reach the end and bounce back.
+    // After enough ticks, offset should return to 0.
+    let mut seen_nonzero = false;
+    let mut returned_to_zero = false;
+    for _ in 0..2000 {
+        scroll.tick(Duration::from_millis(50));
+        if scroll.offset() > 0 {
+            seen_nonzero = true;
+        }
+        if seen_nonzero && scroll.offset() == 0 {
+            returned_to_zero = true;
+            break;
+        }
+    }
+    assert!(seen_nonzero, "should have scrolled");
+    assert!(returned_to_zero, "should have bounced back to 0");
+}
+
+#[test]
+fn reset_restarts_scroll() {
+    let mut scroll = ScrollState::new(100, 200);
+    for _ in 0..100 {
+        scroll.tick(Duration::from_millis(100));
+    }
+    scroll.reset(100, 200);
+    assert_eq!(scroll.offset(), 0);
+}