bevy_bundled_bundle.rs

use bevy::prelude::*;

#[derive(Default)]
struct A;
#[derive(Default, Bundle)]
struct B { a: A }
#[derive(Default, Bundle)]
struct C { b: B }

fn sys(query_a: Query<&A>, query_b: Query<&B>) {
	assert!(query_a.iter().count() == 2);
	assert!(query_b.iter().count() == 2);
}

fn startup(commands: &mut Commands) {
	commands.spawn(C::default()).spawn(B::default()).spawn((A::default(), ));
}

fn main() {
	App::build().add_startup_system(startup.system()).add_system(sys.system()).run();
}

// Resulting in:
// thread 'TaskPool (2)' panicked at 'assertion failed: query_b.iter().count() == 2', src/main.rs:12:3

// Expected result:
// first assert asserting
// second one not asserting
// Because entity with C also have B thus also A
// Entity B also have A
// + another A entity
// == 3 entity having A; 2 entity having B