Added tests to ButtonAxisSettings (#3272)

# Objective

`ButtonAxisSettings` wasn't tested properly.

## Solution

I added tests and fixed issue with `filter` method


Co-authored-by: CrazyRoka <rokarostuk@gmail.com>

crates/bevy_input/src/gamepad.rs

@@ -186,17 +186,20 @@ impl Default for ButtonAxisSettings {
 
 impl ButtonAxisSettings {
     fn filter(&self, new_value: f32, old_value: Option<f32>) -> Option<f32> {
+        let new_value = if new_value <= self.low {
+            0.0
+        } else if new_value >= self.high {
+            1.0
+        } else {
+            new_value
+        };
+
         if let Some(old_value) = old_value {
             if (new_value - old_value).abs() <= self.threshold {
                 return None;
             }
         }
-        if new_value <= self.low {
+
-            return Some(0.0);
-        }
-        if new_value >= self.high {
-            return Some(1.0);
-        }
         Some(new_value)
     }
 }
@@ -306,3 +309,64 @@ const ALL_AXIS_TYPES: [GamepadAxisType; 8] = [
     GamepadAxisType::DPadX,
     GamepadAxisType::DPadY,
 ];
+
+#[cfg(test)]
+mod tests {
+    use super::ButtonAxisSettings;
+
+    fn test_button_axis_settings_filter(
+        settings: ButtonAxisSettings,
+        new_value: f32,
+        old_value: Option<f32>,
+        expected: Option<f32>,
+    ) {
+        let actual = settings.filter(new_value, old_value);
+        assert_eq!(
+            expected, actual,
+            "Testing filtering for {:?} with new_value = {:?}, old_value = {:?}",
+            settings, new_value, old_value
+        );
+    }
+
+    #[test]
+    fn test_button_axis_settings_default_filter() {
+        let cases = [
+            (1.0, None, Some(1.0)),
+            (0.99, None, Some(1.0)),
+            (0.96, None, Some(1.0)),
+            (0.95, None, Some(1.0)),
+            (0.9499, None, Some(0.9499)),
+            (0.84, None, Some(0.84)),
+            (0.43, None, Some(0.43)),
+            (0.05001, None, Some(0.05001)),
+            (0.05, None, Some(0.0)),
+            (0.04, None, Some(0.0)),
+            (0.01, None, Some(0.0)),
+            (0.0, None, Some(0.0)),
+        ];
+
+        for (new_value, old_value, expected) in cases {
+            let settings = ButtonAxisSettings::default();
+            test_button_axis_settings_filter(settings, new_value, old_value, expected);
+        }
+    }
+
+    #[test]
+    fn test_button_axis_settings_default_filter_with_old_value() {
+        let cases = [
+            (0.43, Some(0.44001), Some(0.43)),
+            (0.43, Some(0.44), None),
+            (0.43, Some(0.43), None),
+            (0.43, Some(0.41999), Some(0.43)),
+            (0.43, Some(0.17), Some(0.43)),
+            (0.43, Some(0.84), Some(0.43)),
+            (0.05, Some(0.055), Some(0.0)),
+            (0.95, Some(0.945), Some(1.0)),
+        ];
+
+        for (new_value, old_value, expected) in cases {
+            let settings = ButtonAxisSettings::default();
+            test_button_axis_settings_filter(settings, new_value, old_value, expected);
+        }
+    }
+}