Confused on how to trigger signal/resource use warnings

[lukexor]

Describe the bug

I've seen the warnings emitted by leptos when using signals outside of a reactive context, or resources outside of suspense, but I haven't seen them in my own project and confused as to why.

I was able to set up a scenario where they should be triggered but I still don't see them.

Leptos Dependencies

v0.8.2 leptos todo_app_sqlite_axum example

To Reproduce

• Add the following items to the example (pulled from a closed issue on the same topic)

async fn load_data(count: ReadSignal<i32>, set_count: WriteSignal<i32>) {
    let new_data = move || count.get() + 1;
    set_count.set(new_data());
}

#[component]
pub fn BlockNumber() -> impl IntoView {
    let (count, set_count) = signal(0); // Warning line number

    let action = Action::new(
        |&(count, set_count): &(ReadSignal<i32>, WriteSignal<i32>)| async move {
            load_data(count, set_count).await
        },
    );

    view! {
        <p>{move || count.get()}</p>
        <button on:click=move |_| {
            action.dispatch((count, set_count));
        }>Click</button>
    }
}

• And add <BlockNumber /> to one of the views.
• Run cargo leptos watch
• Click the button

A warning should be logged about reading a signal non-reactively

I also tried an even simpler version with no warnings either:

#[component]
pub fn Counter() -> impl IntoView {
    let (count, set_count) = signal(0);

    view! {
        <p>{count.get()}</p>
        <button on:click=move |_| {
            set_count.set(count.get() + 1);
        }>Click</button>
    }
}

I haven't been able to see warnings for using Resource outside of suspense either.

Is there something I'm missing? I see in the source that it relies on debug_assertions and effects, as well as being outside of a SpecialNonReactiveZone and as far as I can tell all those conditions should be true.

[gbj]

The warnings are suppressed in event handlers, because you would not expect an event handler to re-run reactively in any case. i.e., you have an on:click handler that dispatches an action: this should run when the user clicks, not once when the user clicks and then again whenever the values of any signals read in the click handler change. So I would not expect a warning in the first example, as far as I can tell. (The use of the event handler is what makes this different from #2375 where you got load_data)

When I try your second, Counter example (for example, by copying and pasting it into todo_app_sqlite_axum before the <TodoApp/>) I do get a warning.

[lukexor]

That makes sense. Interesting why I'm not in that second example. I know I've seen them before in other examples/testing so I'll try and figure out what's wrong with my environment

[luxalpa]

Maybe a filter set / unset in your dev console? Does it show other warnings?

[lukexor]

Maybe a filter set / unset in your dev console? Does it show other warnings?

Nope. Using the same browser on a new start-axum project and I get the warnings just fine.

I'm not really sure what else to check.

Even something like this at the root of the app throws a warning in a new project, but not my main project:

    let (is_routing, set_is_routing) = signal(false);
    leptos::logging::log!("routing: {}", is_routing.get());

[lukexor]

I figured it out. I had recently turned on the "tracing" feature of leptos.

This code path for log_warning is unconditional based on target, and so in the browser it won't log unless you have a tracing_subscriber set up for wasm:

    #[cfg(feature = "tracing")]
    {
        tracing::warn!(text);
    }