Works

src/app.rs

@@ -52,6 +52,14 @@ fn get_camera_rotation(app: &mut App) -> f32 {
     transform.rotation.z
 }
 
+#[cfg(test)]
+fn get_camera_zoom(app: &mut App) -> f32 {
+    let mut query = app.world_mut().query::<(&OrthographicProjection, &Camera)>();
+    let (projection, _) = query.single(app.world());
+    projection.scale
+}
+
+
 #[cfg(test)]
 fn get_player_position(app: &mut App) -> Vec2 {
     let mut query = app.world_mut().query::<(&Transform, &Player)>();
@@ -73,10 +81,10 @@ fn count_n_cameras(app: &mut App) -> usize {
 }
 
 fn respond_to_keyboard(
-    mut query: Query<(&mut Transform, &Camera)>,
+    mut query: Query<(&mut Transform, &mut OrthographicProjection, &Camera)>,
     input: Res<ButtonInput<KeyCode>>,
 ) {
-    let (mut transform, _) = query.single_mut();
+    let (mut transform, mut projection, _) = query.single_mut();
     use bevy::input::keyboard::KeyCode;
     if input.pressed(KeyCode::ArrowRight) {
         transform.translation.x += 1.0;
@@ -96,6 +104,12 @@ fn respond_to_keyboard(
     if input.pressed(KeyCode::KeyE) {
         transform.rotate_z(0.1);
     }
+    if input.pressed(KeyCode::KeyW) {
+        projection.scale /= 1.1
+    }
+    if input.pressed(KeyCode::KeyS) {
+        projection.scale *= 1.1
+    }
 }
 
 
@@ -149,6 +163,13 @@ mod tests {
         assert_eq!(get_camera_rotation(&mut app), 0.0);
     }
 
+    #[test]
+    fn test_camera_is_not_zoomed_in_or_out_at_start() {
+        let mut app = create_app();
+        app.update();
+        assert_eq!(get_camera_zoom(&mut app), 1.0);
+    }
+
     #[test]
     fn test_camera_moves_when_pressed_up() {
         let mut app = create_app();
@@ -235,4 +256,33 @@ mod tests {
         assert_ne!(get_camera_rotation(&mut app), 0.0);
     }
 
+    #[test]
+    fn test_camera_zooms_in_when_pressed_w() {
+        let mut app = create_app();
+        app.update();
+        assert_eq!(get_camera_zoom(&mut app), 1.0);
+
+        // Press the key
+        app.world_mut()
+            .resource_mut::<ButtonInput<KeyCode>>()
+            .press(KeyCode::KeyW);
+        app.update();
+
+        assert!(get_camera_zoom(&mut app) < 1.0);
+    }
+    #[test]
+    fn test_camera_zoom_out_when_pressed_s() {
+        let mut app = create_app();
+        app.update();
+        assert_eq!(get_camera_zoom(&mut app), 1.0);
+
+        // Press the key
+        app.world_mut()
+            .resource_mut::<ButtonInput<KeyCode>>()
+            .press(KeyCode::KeyS);
+        app.update();
+
+        assert!(get_camera_zoom(&mut app) > 1.0);
+    }
+
 }