dioxus/packages/core/tests/event_propagation.rs

use dioxus::prelude::*;
use dioxus_core::ElementId;
use std::{rc::Rc, sync::Mutex};

static CLICKS: Mutex<usize> = Mutex::new(0);

#[test]
fn events_propagate() {
    let mut dom = VirtualDom::new(app);
    _ = dom.rebuild();

    // Top-level click is registered
    dom.handle_event("click", Rc::new(MouseData::default()), ElementId(1), true);
    assert_eq!(*CLICKS.lock().unwrap(), 1);

    // break reference....
    for _ in 0..5 {
        dom.mark_dirty(ScopeId(0));
        _ = dom.render_immediate();
    }

    // Lower click is registered
    dom.handle_event("click", Rc::new(MouseData::default()), ElementId(2), true);
    assert_eq!(*CLICKS.lock().unwrap(), 3);

    // break reference....
    for _ in 0..5 {
        dom.mark_dirty(ScopeId(0));
        _ = dom.render_immediate();
    }

    // Stop propagation occurs
    dom.handle_event("click", Rc::new(MouseData::default()), ElementId(2), true);
    assert_eq!(*CLICKS.lock().unwrap(), 3);
}

fn app(cx: Scope) -> Element {
    render! {
        div {
            onclick: move |_| {
                println!("top clicked");
                *CLICKS.lock().unwrap() += 1;
            },

            vec![
                render! {
                    problematic_child {}
                }
            ].into_iter()
        }
    }
}

fn problematic_child(cx: Scope) -> Element {
    render! {
        button {
            onclick: move |evt| {
                let mut clicks = CLICKS.lock().unwrap();

                if *clicks == 3 {
                    evt.stop_propagation();
                } else {
                    *clicks += 1;
                }
            }
        }
    }
}