From cc663c0a05e962da1f88c3bc5d48e563e78a9949 Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Thu, 16 Apr 2026 13:34:32 +0000
Subject: [PATCH] =?UTF-8?q?=F0=9F=A7=AA=20Add=20test=20for=20`update=5Frhy?=
 =?UTF-8?q?thm=5Ffrom=5Fslider`?=
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Added a unit test for the `update_rhythm_from_slider` UI system to ensure it correctly updates the `RhythmState` duration, `HighlightTimer`, and `Text` when the slider value changes. Includes tests for snapping and early-return threshold.

Co-authored-by: dynamikdev <717692+dynamikdev@users.noreply.github.com>
---
 src/ui/mod.rs          |  2 ++
 src/ui/systems_test.rs | 57 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 59 insertions(+)
 create mode 100644 src/ui/systems_test.rs

diff --git a/src/ui/mod.rs b/src/ui/mod.rs
index f77092d..ba51e35 100644
--- a/src/ui/mod.rs
+++ b/src/ui/mod.rs
@@ -12,6 +12,8 @@ mod setup_test;
 #[cfg(test)]
 mod curriculum_test;
 pub mod systems;
+#[cfg(test)]
+mod systems_test;
 pub mod target;
 
 use bevy::prelude::*;
diff --git a/src/ui/systems_test.rs b/src/ui/systems_test.rs
new file mode 100644
index 0000000..dfe2b09
--- /dev/null
+++ b/src/ui/systems_test.rs
@@ -0,0 +1,57 @@
+use bevy::prelude::*;
+use bevy_ui_widgets::SliderValue;
+use std::time::Duration;
+
+use crate::components::RhythmText;
+use crate::resources::{RhythmState, HighlightTimer, RhythmMode};
+use crate::ui::systems::update_rhythm_from_slider;
+
+#[test]
+fn test_update_rhythm_from_slider() {
+    let mut app = App::new();
+
+    // Set up resources.
+    app.insert_resource(RhythmState {
+        duration: 1.0,
+        mode: RhythmMode::Constant,
+        accelerate_counter: 0,
+    });
+    app.insert_resource(HighlightTimer(Timer::from_seconds(1.0, TimerMode::Repeating)));
+
+    // Spawn an entity with the RhythmText component.
+    let text_entity = app.world_mut().spawn((
+        Text("Rhythm: 1.0s".to_string()),
+        RhythmText,
+    )).id();
+
+    // Spawn an entity with SliderValue and manually trigger the `Changed` state.
+    // The value 1.55 should be rounded to 1.6 by the system.
+    let slider_entity = app.world_mut().spawn(SliderValue(1.55)).id();
+
+    app.add_systems(Update, update_rhythm_from_slider);
+
+    // Run the system once. The initial slider spawn should trigger the `Changed` filter.
+    app.update();
+
+    // Check that RhythmState was updated and rounded correctly.
+    let rhythm_state = app.world().get_resource::<RhythmState>().unwrap();
+    assert_eq!(rhythm_state.duration, 1.6);
+
+    // Check that HighlightTimer was updated.
+    let highlight_timer = app.world().get_resource::<HighlightTimer>().unwrap();
+    assert_eq!(highlight_timer.0.duration(), Duration::from_secs_f32(1.6));
+
+    // Check that the text component was updated.
+    let text_component = app.world().get::<Text>(text_entity).unwrap();
+    assert_eq!(text_component.0, "Rhythm: 1.6s");
+
+    // Test early return for small changes.
+    // Update the slider to a value very close to the current rounded value (1.6).
+    app.world_mut().entity_mut(slider_entity).insert(SliderValue(1.605));
+    app.update();
+
+    // The state should remain unchanged (1.6) because the absolute difference
+    // between 1.6 and (1.605 * 10).round() / 10.0 => 1.6 is 0.0, which is < 0.01.
+    let rhythm_state = app.world().get_resource::<RhythmState>().unwrap();
+    assert_eq!(rhythm_state.duration, 1.6);
+}